Thanks for dedicating time for my project! Haha, your kind feedback really make me happy that the game makes someone engaged :D. I'll surely change speed of accelerating difficulty curve and lower down the prices after the jam is over and I'm able to release patches.
You've said you bought some upgrades at the shop... Can you please tell me if you bought second level of any upgrade? I know about an issue that upon purchasing second level of any upgrade at the shop the HTML version of the game can just freeze and crash. It would be really helpful if you replied on it, since I myself have this problem.
Also, I'll make sure to check and rate your submission as well.
Have a nice day!