Thanks for playing the game and thanks for the feedback!
Yes, the enemies are too strong. If you do not get "attack", "attack combo" or "turn" in the first chests you cannot really make it. I only had around 10 minutes to balance it.
I thought prices were OK, if you get past the initial stages. You get the same amount of coins as the stages you have cleared. Enemies on the 4th stage gives 4 coins. The power ups that costs 15 are quite overpowered too, "attack combo" and "turn" basically gives you double damage and health because you can make things twice as many times as the enemies.
I tried to make the game using a single tilesheet (40x40) with only 6 colors. This was mainly because I am a very bad artist and I cannot draw anything that looks good (same reason why I did not animate the character or enemies).
I love the feedback and I will try to update the game after the Jam will all the feedback I got!