Why?

1. Only 2 main weapons, and 2 secondary weapons per class
2. Perks, are mostly passive bonus, like +X damage, or +X ammo
3. Monsters though a few, are all the same. You are going to fight spiders over and over again.
4. Missions are extremely repetitive
5. The customization looks great at first sight but is actually pretty shallow and simplistic.

Of course, that does not take away the great qualities this game has: the fun cooperative gameplay, the great art direction and music.

But that's it, to be honest, do not trust the "overwhelmingly positive reviews" of steam. I would give this game a 6.5/10 and perhaps a 7/10 max for the humor and good vibes the game has. However, games like Killing Floor or even Left 4 Dead do so much more for less money. Actually even Vermintide might be a better pick than this.

Rock & Stone? More like Flop & Done.

Shallow Rock Galactic: not for me.