@LordHylas I like the mechanic. The money isn't necessary (you get towers for completing levels" but it is a nice perk to keep you playing a level after you've beaten it until your perfect.
Even with your credit I think it takes too much from Zeebarf's game. Generally when you are going to do a take on someone's content you try and add something different to it. I found the controls to be more frustrating and the story to be less motivating. Clearly your talented, but for all the work I think this game under-delivers.