This is Jack from Year 1. My biggest complaint is the motion blur. It hurts my eyes. The other thing I would change would be increasing the cost proportionally to its level. I notice that after a couple levels in one skill it just becomes impossible to die. Another thing I noticed was that later game the penguins weren't threatening enough. Also scale the pixel art up by nearest neighbor that should fix the blurriness of the art. Pretty cool game though and I'm sad that at least one penguin died.