Free sandbox open world, zombie, multiplayer/ co-op survival games? Like 7 days to die?

Hi, i'm looking for a first or third person 3d open world game where you can build and destroy structures like in minecraft with multiplayer co op to play with friends. I would also like the hostile npcs of the game to be able to destroy the blocks like in 7 days to die and the buildings could collapse, so no floating structures to make it more challenging. Preferably with low specs and low price. Does anyone know any games that fit this description? Please no garrys mod or single player games as an answer. I enjoyed 7 days to die up to a point but it was a little glitchy and minecraft the mobs arent really challenging since they don't destroy your blocks(besides creepers) but they arent dangerous since you can stay inside or build floating structures.