Recent reviews by Bruhl

A worthy successor to the original Hammerwatch that improves on its predecessor in a variety of ways.

The most obvious improvement is the graphics. The game features beautiful pixel-graphics with much more clearly readable sprites than either Hammerwatch or even Heros of Hammerwatch. The controls have also been vastly improved compared to the first game.
Gameplaywise, HM II features a lot more RPG elements than HM like quests, buildcrafting and random item pick ups. Combined with five different playable classes and four difficulty levels this gives the game a lot more replay-value and that's not to speak of day 1 mod-support.

Regarding the most common criticism, the save system, I don't know what people have expected. Having your character of a multiplayer session only saved on the host-side is common practice for online co-op RPGs, Baldur's Gate 3 uses the same system and it just released to critical acclaim. This is an RPG where you play the story with friends and then are done with the run, not an MMO where you spend hundreds of hours grinding your character.
Also people seem to be disappointed that the game is so different to Heroes of Hammerwatch when it isn't even the successor to that game.

That said, exploring can sometimes feel a little underwhelming with dead-ends leading to nothing but common item pickups but this is far from a dealbreaker to me.

I hope that when mankind has vanished in the distant future and alien races find our abandoned planet, all that is left of the human civilization is Bad Rats: the Rats' Revenge.