I agree with the other commenter that the actual shots fired by the towers seemed less powerful than just placing towers, to the point where the healing phases were actually detrimental as I couldn't place more towers! This was surprisingly fun though, I did stick it out until I managed to get to the end :)

I think this game has an interesting idea to it, that being that placing towers has the side effect of costing health to the main base and local towers, which needs to be recovered at a later phase. I think that this game could do better with a scaling down of the number of enemies and an increased variety in the number of towers and enemies.

Additionally The tower placement probably shouldn't damage the enemies if one wants this to be a conventional tower defense game. It gets to the point where the damage from placing the towers is more relevant to enemy crowd control than their actual shots. I think if you toned down the number of enemies and had them come in wave, along with allowing the user to buy blocks that the enemies have to go around at the cost of health, you could have a fairly interesting tower defense game where their is a push and pull as to how many resources someone wants to play at the cost of their tower. The main reason why I recommend this pursuit in development is that the game eventually devolved for me to just repeatedly placing towers far away from my main tower (whether or not the damage decreases by distance or by number of enemies hit I don't know as their were always a lot of them) and the fundamental issue with this is it removes any element of strategy one might which is what many people who play tower defense games really like.

Overall it is a surprisingly fun game that I find myself trying to get a high score on (thus far 6127) but it lacks the depth necessary to make it engaging after the 3rd attempt.