Spawner and Boss Enemies and Final Level

Spawner Enemy

Added the spawner enemy, which splits into two normal enemies of the same type when killed, and appears on level 18.

Boss Enemy

Added the boss enemy, which splits into two spawner enemies of random types once killed, and appears on level 24 (the last level)

Final Level

Tweaked the weights and enemy count for the last level so that one boss enemy would appear right at the end

Playtesting

Finished testing all the levels of the game and adjusted the weights and speeds of enemies to make later levels easier

Debugging

Fixed an issue where killing any spawned enemy would result in winning the level prematurely, and fixed the tutorial level, which had broken after recent changes

QoL Updates

Updated the checkmark asset to a better version, added an exit button to the main menu, and made enemies stop spawning after the count has been reached