Good game! I liked the graphics and it's fun to play! But I think it's more hard than should be. The delay of the weapon and quantity of hits to kill the enemies at first levels it's a bit frustrating...
Sometimes on later levels, a group of 3 or 5 enemies spawn exactly where the player is, applying some unfair damage. I played a lot of times to finally win the game, feeling that at this run, the game randomness was on my side (there are some "trash" upgrade cards and some very necessary and powered cards). Also, I feel the only way to beat the game is attacking a group of enemies at same time, otherwise, there is no time to beat the enemies and collect wood and food before frost.
Anyway, nice entry! =)