Fun game! A bit rough on feedback and impact, I couldn't figure out if the abilities had any effects other than amount of damage they caused. Maybe you could add effects like ice will slow an enemy's attack speed. I would also suggest having a explanation of the abilities when you're on the upgrade screen, and a way to see how much gold you possess. (unless I missed that part, lol.) Also you should consider allowing enter to proceed from the start menu, I got irritated having to pull my hand off the arrow keys to try again.