Cost to upgrade a skill to lvl 10 is insane. Lowering both the cost and the effect could be good. I completed all the badges in 20 chapters. Having everything maxed out of at lvl 5/10. That is pretty much the end of the game... Adding more challenges, a 4th purchasable/unlockable act, maybe an endless mode (once you can fix all the lags due to number of monsters/orbs/dmg tags). Act 3 falling folk dance makes the game soooo laggy when you use lazers as the monsters have so much life, they are barely killable.