I really like this one a lot! The art is cool and I like the little touches of detail in the background. The game could use a little more vfx (nice explosions!), maybe add some screen-shake, or other particle effects. I really like how many unlockables there are. I played 22 rounds trying to save up for the grenade launcher, but it seemed like the credits would stop rolling in halfway though the battle. not sure if this is a bug, or caused by the enemy advance. Great work, either way, it's a very cool prototype :)