This Game is pretty fun, I really like the method of walking the zombies near other graves before killing them so you can summon more zombies faster. For a game-jam game it feels pretty full and fleshed out, especially your first. If you wanted to continue this idea There's a lot of ways to expand and you have something pretty unique. Only real critique for the time limit is some of the art could be better but none of it sticks out as especially bad. Great job!