diff --git a/Backends/HTML5/kha/LoaderImpl.hx b/Backends/HTML5/kha/LoaderImpl.hx
index acf27d2b6..355f1227b 100644
--- a/Backends/HTML5/kha/LoaderImpl.hx
+++ b/Backends/HTML5/kha/LoaderImpl.hx
@@ -1,16 +1,16 @@
 package kha;
 
-import js.html.FileReader;
-import js.Syntax;
+import haxe.io.Bytes;
 import js.Browser;
+import js.Syntax;
+import js.html.FileReader;
 import js.html.ImageElement;
 import js.html.XMLHttpRequest;
-import haxe.io.Bytes;
 import kha.Blob;
-import kha.js.WebAudioSound;
-import kha.js.MobileWebAudioSound;
 import kha.graphics4.TextureFormat;
 import kha.graphics4.Usage;
+import kha.js.MobileWebAudioSound;
+import kha.js.WebAudioSound;
 
 using StringTools;
 
@@ -22,7 +22,7 @@ class LoaderImpl {
 		return ["png", "jpg", "hdr"];
 	}
 
-	public static function loadImageFromDescription(desc: Dynamic, done: kha.Image->Void, failed: AssetError->Void) {
+	public static function loadImageFromDescription(desc: Dynamic, done: kha.Image->Void, failed: (err: AssetError) -> Void) {
 		var readable = Reflect.hasField(desc, "readable") ? desc.readable : false;
 		if (StringTools.endsWith(desc.files[0], ".hdr")) {
 			loadBlobFromDescription(desc, function(blob) {
@@ -56,7 +56,7 @@ class LoaderImpl {
 		return formats;
 	}
 
-	public static function loadSoundFromDescription(desc: Dynamic, done: kha.Sound->Void, failed: AssetError->Void) {
+	public static function loadSoundFromDescription(desc: Dynamic, done: kha.Sound->Void, failed: (err: AssetError) -> Void) {
 		if (SystemImpl._hasWebAudio) {
 			#if !kha_debug_html5
 			var element = Browser.document.createAudioElement();
@@ -154,11 +154,11 @@ class LoaderImpl {
 		#end
 	}
 
-	public static function loadVideoFromDescription(desc: Dynamic, done: kha.Video->Void, failed: AssetError->Void): Void {
+	public static function loadVideoFromDescription(desc: Dynamic, done: kha.Video->Void, failed: (err: AssetError) -> Void): Void {
 		kha.js.Video.fromFile(desc.files, done);
 	}
 
-	public static function loadRemote(desc: Dynamic, done: Blob->Void, failed: AssetError->Void) {
+	public static function loadRemote(desc: Dynamic, done: Blob->Void, failed: (err: AssetError) -> Void) {
 		var request = untyped new XMLHttpRequest();
 		request.open("GET", desc.files[0], true);
 		request.responseType = "arraybuffer";
@@ -194,7 +194,7 @@ class LoaderImpl {
 		request.send(null);
 	}
 
-	public static function loadBlobFromDescription(desc: Dynamic, done: Blob->Void, failed: AssetError->Void) {
+	public static function loadBlobFromDescription(desc: Dynamic, done: Blob->Void, failed: (err: AssetError) -> Void) {
 		#if kha_debug_html5
 		var file: String = desc.files[0];
 
@@ -228,7 +228,7 @@ class LoaderImpl {
 		#end
 	}
 
-	public static function loadFontFromDescription(desc: Dynamic, done: Font->Void, failed: AssetError->Void): Void {
+	public static function loadFontFromDescription(desc: Dynamic, done: Font->Void, failed: (err: AssetError) -> Void): Void {
 		loadBlobFromDescription(desc, function(blob: Blob) {
 			done(new Font(blob));
 		}, failed);
diff --git a/Backends/HTML5/kha/audio2/Audio.hx b/Backends/HTML5/kha/audio2/Audio.hx
index e659e21b3..3ef780fb9 100644
--- a/Backends/HTML5/kha/audio2/Audio.hx
+++ b/Backends/HTML5/kha/audio2/Audio.hx
@@ -1,14 +1,14 @@
 package kha.audio2;
 
-import js.Syntax;
 import js.Browser;
+import js.Syntax;
 import js.html.URL;
 import js.html.audio.AudioContext;
 import js.html.audio.AudioProcessingEvent;
 import js.html.audio.ScriptProcessorNode;
+import kha.Sound;
 import kha.internal.IntBox;
 import kha.js.AEAudioChannel;
-import kha.Sound;
 
 class Audio {
 	public static var disableGcInteractions = false;
@@ -70,7 +70,7 @@ class Audio {
 
 	public static var samplesPerSecond: Int;
 
-	public static var audioCallback: kha.internal.IntBox->Buffer->Void;
+	public static var audioCallback: (outputBufferLength: IntBox, buffer: Buffer) -> Void;
 
 	static var virtualChannels: Array<VirtualStreamChannel> = [];
 
diff --git a/Sources/kha/Assets.hx b/Sources/kha/Assets.hx
index 605433ac6..3f0958def 100644
--- a/Sources/kha/Assets.hx
+++ b/Sources/kha/Assets.hx
@@ -1,7 +1,7 @@
 package kha;
 
-import haxe.io.Bytes;
 import haxe.Unserializer;
+import haxe.io.Bytes;
 
 using StringTools;
 
@@ -144,16 +144,14 @@ class Assets {
 			onLoaded(bytes);
 		}
 
-		function loadFunc(desc: Dynamic, done: (bytes: Int) -> Void, failure: (err: AssetError, bytes: Int) -> Void): Void {
+		function loadFunc(desc: AssetData, done: (bytes: Int) -> Void, failure: (err: AssetError, bytes: Int) -> Void): Void {
 			final name = desc.name;
 			final size = desc.file_sizes[0];
 			switch (desc.type) {
 				case "image":
-					Assets.loadImage(name, function(image: Image) done(size), function(err: AssetError) {
-						onError(err, size);
-					});
+					Assets.loadImage(name, image -> done(size), err -> onError(err, size));
 				case "sound":
-					Assets.loadSound(name, function(sound: Sound) {
+					Assets.loadSound(name, sound -> {
 						if (uncompressSoundsFilter == null || uncompressSoundsFilter(desc)) {
 							sound.uncompress(function() {
 								done(size);
@@ -162,21 +160,13 @@ class Assets {
 						else {
 							done(size);
 						}
-					}, function(err: AssetError) {
-						onError(err, size);
-					});
+					}, err -> onError(err, size));
 				case "blob":
-					Assets.loadBlob(name, function(blob: Blob) done(size), function(err: AssetError) {
-						onError(err, size);
-					});
+					Assets.loadBlob(name, blob -> done(size), err -> onError(err, size));
 				case "font":
-					Assets.loadFont(name, function(font: Font) done(size), function(err: AssetError) {
-						onError(err, size);
-					});
+					Assets.loadFont(name, font -> done(size), err -> onError(err, size));
 				case "video":
-					Assets.loadVideo(name, function(video: Video) done(size), function(err: AssetError) {
-						onError(err, size);
-					});
+					Assets.loadVideo(name, video -> done(size), err -> onError(err, size));
 			}
 		}
 
@@ -203,7 +193,7 @@ class Assets {
 	 * @param	name The name as defined by the khafile.
 	 * @param	done A callback.
 	 */
-	public static function loadImage(name: String, done: Image->Void, ?failed: AssetError->Void, ?pos: haxe.PosInfos): Void {
+	public static function loadImage(name: String, done: (image: Image) -> Void, ?failed: (err: AssetError) -> Void, ?pos: haxe.PosInfos): Void {
 		var description = Reflect.field(images, name + "Description");
 		if (description == null) {
 			reporter(failed, pos)({url: name, error: "Name not found"});
@@ -222,7 +212,8 @@ class Assets {
 	 * @param   readable If true, a copy of the image will be kept in main memory for image read operations.
 	 * @param	done A callback.
 	 */
-	public static function loadImageFromPath(path: String, readable: Bool, done: Image->Void, ?failed: AssetError->Void, ?pos: haxe.PosInfos): Void {
+	public static function loadImageFromPath(path: String, readable: Bool, done: (image: Image) -> Void, ?failed: (err: AssetError) -> Void,
+			?pos: haxe.PosInfos): Void {
 		var description = {files: [path], readable: readable};
 		LoaderImpl.loadImageFromDescription(description, done, reporter(failed, pos));
 	}
@@ -233,7 +224,7 @@ class Assets {
 		return LoaderImpl.getImageFormats();
 	}
 
-	public static function loadBlob(name: String, done: Blob->Void, ?failed: AssetError->Void, ?pos: haxe.PosInfos): Void {
+	public static function loadBlob(name: String, done: (blob: Blob) -> Void, ?failed: (err: AssetError) -> Void, ?pos: haxe.PosInfos): Void {
 		var description = Reflect.field(blobs, name + "Description");
 		if (description == null) {
 			reporter(failed, pos)({url: name, error: "Name not found"});
@@ -245,12 +236,12 @@ class Assets {
 		}, reporter(failed, pos));
 	}
 
-	public static function loadBlobFromPath(path: String, done: Blob->Void, ?failed: AssetError->Void, ?pos: haxe.PosInfos): Void {
+	public static function loadBlobFromPath(path: String, done: (blob: Blob) -> Void, ?failed: (err: AssetError) -> Void, ?pos: haxe.PosInfos): Void {
 		var description = {files: [path]};
 		LoaderImpl.loadBlobFromDescription(description, done, reporter(failed, pos));
 	}
 
-	public static function loadSound(name: String, done: Sound->Void, ?failed: AssetError->Void, ?pos: haxe.PosInfos): Void {
+	public static function loadSound(name: String, done: (sound: Sound) -> Void, ?failed: (err: AssetError) -> Void, ?pos: haxe.PosInfos): Void {
 		var description = Reflect.field(sounds, name + "Description");
 		if (description == null) {
 			reporter(failed, pos)({url: name, error: "Name not found"});
@@ -262,7 +253,7 @@ class Assets {
 		}, reporter(failed, pos));
 	}
 
-	public static function loadSoundFromPath(path: String, done: Sound->Void, ?failed: AssetError->Void, ?pos: haxe.PosInfos): Void {
+	public static function loadSoundFromPath(path: String, done: (sound: Sound) -> Void, ?failed: (err: AssetError) -> Void, ?pos: haxe.PosInfos): Void {
 		var description = {files: [path]};
 		return LoaderImpl.loadSoundFromDescription(description, done, reporter(failed, pos));
 	}
@@ -273,7 +264,7 @@ class Assets {
 		return LoaderImpl.getSoundFormats();
 	}
 
-	public static function loadFont(name: String, done: Font->Void, ?failed: AssetError->Void, ?pos: haxe.PosInfos): Void {
+	public static function loadFont(name: String, done: (font: Font) -> Void, ?failed: (err: AssetError) -> Void, ?pos: haxe.PosInfos): Void {
 		var description = Reflect.field(fonts, name + "Description");
 		if (description == null) {
 			reporter(failed, pos)({url: name, error: "Name not found"});
@@ -285,7 +276,7 @@ class Assets {
 		}, reporter(failed, pos));
 	}
 
-	public static function loadFontFromPath(path: String, done: Font->Void, ?failed: AssetError->Void, ?pos: haxe.PosInfos): Void {
+	public static function loadFontFromPath(path: String, done: (font: Font) -> Void, ?failed: (err: AssetError) -> Void, ?pos: haxe.PosInfos): Void {
 		var description = {files: [path]};
 		return LoaderImpl.loadFontFromDescription(description, done, reporter(failed, pos));
 	}
@@ -296,7 +287,7 @@ class Assets {
 		return ["ttf"];
 	}
 
-	public static function loadVideo(name: String, done: Video->Void, ?failed: AssetError->Void, ?pos: haxe.PosInfos): Void {
+	public static function loadVideo(name: String, done: (video: Video) -> Void, ?failed: (err: AssetError) -> Void, ?pos: haxe.PosInfos): Void {
 		var description = Reflect.field(videos, name + "Description");
 		if (description == null) {
 			reporter(failed, pos)({url: name, error: "Name not found"});
@@ -308,7 +299,7 @@ class Assets {
 		}, reporter(failed, pos));
 	}
 
-	public static function loadVideoFromPath(path: String, done: Video->Void, ?failed: AssetError->Void, ?pos: haxe.PosInfos): Void {
+	public static function loadVideoFromPath(path: String, done: (video: Video) -> Void, ?failed: (err: AssetError) -> Void, ?pos: haxe.PosInfos): Void {
 		var description = {files: [path]};
 		return LoaderImpl.loadVideoFromDescription(description, done, reporter(failed, pos));
 	}
@@ -319,7 +310,7 @@ class Assets {
 		return LoaderImpl.getVideoFormats();
 	}
 
-	public static function reporter(custom: AssetError->Void, ?pos: haxe.PosInfos) {
+	public static function reporter(custom: (err: AssetError) -> Void, ?pos: haxe.PosInfos) {
 		return custom != null ? custom : haxe.Log.trace.bind(_, pos);
 	}
 }
diff --git a/Sources/kha/System.hx b/Sources/kha/System.hx
index 1d4bd1dc5..5301ce812 100644
--- a/Sources/kha/System.hx
+++ b/Sources/kha/System.hx
@@ -103,7 +103,7 @@ class System {
 		});
 	}
 
-	public static function start(options: SystemOptions, callback: Window->Void): Void {
+	public static function start(options: SystemOptions, callback: (window: Window) -> Void): Void {
 		theTitle = options.title;
 		SystemImpl.init(options, callback);
 	}
diff --git a/Sources/kha/audio2/Audio.hx b/Sources/kha/audio2/Audio.hx
index f427ca4cf..90ec48c5f 100644
--- a/Sources/kha/audio2/Audio.hx
+++ b/Sources/kha/audio2/Audio.hx
@@ -1,5 +1,7 @@
 package kha.audio2;
 
+import kha.internal.IntBox;
+
 extern class Audio {
 	/**
 	 * The samples per second natively used by the target system.
@@ -11,7 +13,7 @@ extern class Audio {
 	 * Beware: This is called from a separate audio thread on some targets.
 	 * See kha.audio2.Audio1 for sample code.
 	 */
-	public static var audioCallback: Int->Buffer->Void;
+	public static var audioCallback: (outputBufferLength:IntBox, buffer:Buffer)->Void;
 
 	/**
 	 * Similar to kha.audio1.Audio.stream, but only for hardware accelerated audio playback.
diff --git a/Sources/kha/input/Gamepad.hx b/Sources/kha/input/Gamepad.hx
index 693b7f399..fec7c339d 100644
--- a/Sources/kha/input/Gamepad.hx
+++ b/Sources/kha/input/Gamepad.hx
@@ -1,57 +1,69 @@
 package kha.input;
 
+private typedef GamepadIdCallback = (index: Int) -> Void;
+private typedef GamepadAxisCallback = (axisId: Int, value: Float) -> Void;
+private typedef GamepadButtonCallback = (buttonId: Int, value: Float) -> Void;
+
 @:allow(kha.SystemImpl)
 @:expose
 class Gamepad {
 	var index: Int;
 
-	public static function get(index: Int = 0): Gamepad {
+	public static function get(index: Int = 0): Null<Gamepad> {
 		if (index >= instances.length)
 			return null;
 		return instances[index];
 	}
 
-	public static function notifyOnConnect(?connectListener: Int->Void, ?disconnectListener: Int->Void): Void {
+	/**
+		Use this event to get connected gamepad `index` and listen to it with `Gamepad.get(index).notify(axisListener, buttonListener)`.
+
+		Remember to also check `Gamepad.get(0)`, gamepads may already be connected before the application was initialized.
+	**/
+	public static function notifyOnConnect(?connectListener: GamepadIdCallback, ?disconnectListener: GamepadIdCallback): Void {
 		if (connectListener != null)
 			connectListeners.push(connectListener);
 		if (disconnectListener != null)
 			disconnectListeners.push(disconnectListener);
 	}
 
-	public static function removeConnect(?connectListener: Int->Void, ?disconnectListener: Int->Void): Void {
+	public static function removeConnect(?connectListener: GamepadIdCallback, ?disconnectListener: GamepadIdCallback): Void {
 		if (connectListener != null)
 			connectListeners.remove(connectListener);
 		if (disconnectListener != null)
 			disconnectListeners.remove(disconnectListener);
 	}
 
-	public function notify(?axisListener: Int->Float->Void, ?buttonListener: Int->Float->Void): Void {
+	/**
+		In `axisListener`, `axisId` is axis id (for example `axis == 0` is L-stick `x`, `1` is L-stick `y`, `2` is R-stick `x`, `3` is R-stick `y`, ...) and `value` is in `-1.0 - 1.0` range.
+
+		In `buttonListener`, `buttonId` is pressed button id (layout depends on `vendor`), and `value` is in `0 - 1.0` range how hard the button is pressed.
+	**/
+	public function notify(?axisListener: GamepadAxisCallback, ?buttonListener: GamepadButtonCallback): Void {
 		if (axisListener != null)
 			axisListeners.push(axisListener);
 		if (buttonListener != null)
 			buttonListeners.push(buttonListener);
 	}
 
-	public function remove(?axisListener: Int->Float->Void, ?buttonListener: Int->Float->Void): Void {
+	public function remove(?axisListener: GamepadAxisCallback, ?buttonListener: GamepadButtonCallback): Void {
 		if (axisListener != null)
 			axisListeners.remove(axisListener);
 		if (buttonListener != null)
 			buttonListeners.remove(buttonListener);
 	}
 
-	static var instances: Array<Gamepad> = new Array();
+	static var instances: Array<Gamepad> = [];
 
-	var axisListeners: Array<Int->Float->Void>;
-	var buttonListeners: Array<Int->Float->Void>;
+	var axisListeners: Array<GamepadAxisCallback> = [];
+	var buttonListeners: Array<GamepadButtonCallback> = [];
 
-	static var connectListeners: Array<Int->Void> = new Array();
-	static var disconnectListeners: Array<Int->Void> = new Array();
+	static var connectListeners: Array<GamepadIdCallback> = [];
+	static var disconnectListeners: Array<GamepadIdCallback> = [];
 
 	function new(index: Int = 0, id: String = "unknown") {
 		connected = false;
 		this.index = index;
-		axisListeners = new Array<Int->Float->Void>();
-		buttonListeners = new Array<Int->Float->Void>();
 		instances[index] = this;
 	}