Fun little game, maybe a little stress reducer too for those who don't like orcs. There's a lot to be desired; the lack of audio sort of takes away a bit from the game. Even a bit of audible feedback with the orcs getting crushed or even the hammer just smashing the ground would help a lot! As for gameplay, it is quite grindy. I'm generally okay with it, but I imagine that can potentially be a problem for others if the game feels too repetitive with little to no change for too long. It might help, at least for a prototype, to lower the costs of upgrades to help alleviate this issue. That being said, it was frustrating to smash the last orc with the hammer's remaining hp, having its money pop out, only to be blocked by the game over message preventing me from collecting it. Auto-collecting the money, or just allowing money collection even on game over would be nice.
Regardless, the game was still pretty fun despite its flaws, good work!