Level generation update

Take a look at how the levels have evolved. This isn't the final version yet, but it's already very close to what I want them to look like in the full release.

Before:

Now:

Also:

• The entire UI has been completely redesigned.

• Added freezing barrels and mines.

• Reworked the equipment system. Every armor set now has its own active support ability.

• Added 7 new enemies.

• Added various post-processing visual effects.

• Reworked the damage system. Damage is now divided into Physical, Fire, Lightning, Ice, Holy, Poison, and Bleed types. These affect both Shroomanoid and enemies, with different enemy types having different strengths and weaknesses.

• Reworked the progression system. It now works similarly to the one in Brotato.

• Arrows and other projectiles can now stick into Shroomanoid, enemies, and walls.

• Expanded enemy AI. Shield-bearing enemies will try to protect ranged enemies, while some ranged enemies will attempt to dodge Shroomanoid hits.

• Added 3 new elite rooms.

• Enemies now explode into pieces when killed with a powerful overkill (more than 20% excess damage). This will have a much bigger impact on gameplay in future updates.

• Created proper icons for most equipment.

• Plus many other smaller improvements and bug fixes.