Deep Rock Galactic is just like Left 4 Dead, except you are dwarves. In space. And you are mining. And you kill bugs.
On second thought, only the very basic premise is similar, but they have innovated the **** out of the 4 player co-op template that started with L4D.
Every mission is essentially the same. Go down in your drop-pod. Mine/gather /find the required resources, or kill the required creatures, call down the droppod again and make your escape.
However, the game has a variety of different mission types and many different biomes, ranging from annoying fungus bogs to much chiller glacial caves.
Caves are procedually generated and their system works great. Played about 22 hours this month, and havent encounted a single serious bug with it so far.
With the resources you find, you can buy cosmetics that you unlock as you level up. Or spend them on weapon upgrades. Currently, there are only 2 primary and 2 secondary weapons for each class, but this is likely to change soon. The devs have, from what I have seen, montly updates, with each adding at least something worthwhile.
DRG has 4 very different classes, with every class having a distinct role in the game.
Gunner is the heavy weapons guy, with great firepower come great many kills. But he also has a zipline gun, making areas easily accessible for his whole team.
Engineer can use his platform gun to create platforms. Great to bridge gaps and reach those hard to reach ores.
Scout has a flare gun to light up large caverns for a long time. Also has a grappling hook. He can use it to bravely run away and reach areas no dwarf is meant to go.
Driller drills fast.
You currently fight hordes of bugs. When I played the game last summer, there were A LOT less different enemies. Steam post post-free weekend showing some upcoming creatures and fan-art
Steam store link.