The moment I heard the voice acting I knew exactly who you guys were haha
I remember awhile back you made a tower defense zombie game involving a small variety of units but tons and tons of upgrades. The lack of information given to the player made it a long and trying process of TRIAL and ERROR. My point is, this game suffers terribly from the same design. Instead of simplifying your content, you've made it near impossible to balance the mechanics in the game. Money buys more skill points but also one-time-use weaponry. If you want to stock up on the them you have to grind over and over again if you want a shot at beating the later levels. It gets boring and repetitive. Furthermore, I had no idea they were one-time-use items. The only information you provided was what they did and how much they cost. I ended up spending all of my money on bombs and reinforcements and using them on the early levels just to test them out. After realizing my error I had to go back and grind for more money. It was a vicious and boring cycle.
It's a cool concept but ya gotta keep things simple. Put more focus on troop upgrades instead of extraneous expenses like "YOU HAVE TO USE A BOMB HERE TO TURN THE TIDE OF BATTLE OR YOU WILL LOSE BECAUSE TROOPS ON YOUR SIDE WILL NOT SPAWN FAST ENOUGH AND YOU CAN'T UPGRADE THEM ANYMORE. YOU DIDN'T BUY ANY? OH, WELL MAYBE NEXT TIME :C"