Add the Juice 🥤🍊

[hendriku]

After the game concept and the related physics are working we should concentrate on the quality of the assets, animations, sounds etc. Some important examples are:

• Turret should have a variable blowback and show a firing animation out of the bull barrell at least on higher weapons/firing rates implemented via Implement upgrade system 💵💰 #6.
• Maybe let the bullet rotate after fired.
• Enemies like implemented in Add some enemies 😈 #7 should not only just despawn when hit by a bullet. The bullet should kind of explode(? maybe also on higher weapons) and the enemies should animate their death.
• Attacks of the enemies when nearby a fence or the turret should also be animated.

Look in the literature for explanations and examples for juice.