Hey. It's a nice, little game.
Some of my thoughts:
- Add "start" button. Currently it starts automatically, and before I made a full screen, checked what's happening, I already lost some health, I haven't even noticed the first enemy.
- New weapons should not replace old one. It's a waste of money. Either block new weapons for the tower, or allow to switch weapons.
- It lacks any upgrades to weapons like: speed, damage, etc.
- Maybe consider that once you select a weapon for a tower, instead of other weapons you give upgrades to this weapon.
- Adding an automatic tower would be a nice addition - so tower aims and shoots automatically
- Consider decreasing a difficulty level.