A couple of improvements plus Linux version

A couple of fixes and improvements:

• flamethrower doesn't crash the game anymore due to ridiculous number of unnecessary spawned particles on the floor
• explosions now have clear enemy impact radius
• tower layout have less unexpected places for enemies to drop from
• explosions and disc gun now can damage you — beware and adapt your strategy!
• more contrast and saturation!

And also there's Linux a version now! I've tested in on Steam Deck, let me know if something looks wrong on your distro!