cute artstyle. loved the idea of matching zombies (can be a standalone game).
-- i did not find shooting challenging once i figured it's best not to aim and shoot at the flatest angle. to overcome this i would consider introducing a type of enemy which if not killed in x turns, you lose or it makes the game more challenging (you lose ghosts/bullets or it heals nearby zombies for example).
-- bug: after failing level 1 (match), i could not press the "Level 2" button.
would love if you could also check out my new game, Pop Party! ;-)