For a game about going on a murderous rampage, this is really cute :D I love the idea of having little minigames per upgrade. And the background during those is really evocative, nice shader work! I wish the game was a biiiit more difficult, as I found out on day two that I can keep combos going infinitely by charging into small props in-between attacks. That means that I had to intentionally die to continue in the story!
Very cute little game, and as other commenters said, this would fit lovely into a mobile game store <3