I agree with the other comments regarding the cost of the towers, the best place to have it would have been below each of them when you step on the construction tile. Nevetheless, the game was a lot of fun! I liked the strategy component of knowing when and where to build each tower and the risk/reward of when to go to collect the currency. The first tower I built was the one that shoots in a circular pattern in the middle of the screen and I was fucked for the rest of the game haha.
Great job!!