Needs improvement
Here are my suggestions-
*Improve the graphics
*Fix the bug where, after Nene appears, it gets really hard really quickly
*The music was good, but got annoying after a while, perhaps a mute button too
*Add an easy mode (with more lives, more starting Grounds Gold and enemies with less health)
*Make it so you can see a unit's range, and the range increases when you upgrade
*More maps, with different terrain
Please improve these things, and you will have a brilliant game. For now, it's OK, but not great.