This was a good game. The mechanic has a lot of further potential and puts a nice strategic layer on top of the combat. There are a few things I would modify to make the experience that much better:
Add adequate pathfinding to the goblins so they dont get stuck
Lower the health of the humans so they dont kill you even with 10+ goblins
Fix up the collisions
Overall, with these additions, this would make for a pretty solid release!