What the game is
The Black Pool is a 3D action roguelike from Smug Marmot Studios. Four friends find a black pool in the forest outside of town and get pulled into an unknown galactic system. Each run sends you through a random sequence of diverse worlds, and you fight your way out using supernatural abilities you pick up along the way. The run layout, the abilities offered, and the upgrades change every session, so no two attempts play the same.
You build as you go. There are 90 abilities and augments drawn from 9 elements — Fire, Light, Ice, Decay, Terra, Wind, Lightning, Void, and Chaos — plus 99 upgrades for them. Choosing what to take and what to stack together matters, and improvising a build that works is a core part of the game. Between runs you keep 18 upgradeable device powers that carry over permanently, so you come back stronger and open up different play styles. Enemy behavior also sticks in your head: you learn how the 55 enemies move and what their weaknesses are, including 11 multi-stage bosses.
Playing it as a group
The Black Pool is built for up to 4 players in online co-op, and you can also play it solo. Co-op is not just four people shooting in the same room — many abilities have mechanics that only pay off when you coordinate. You can redirect friendly attacks, amplify each other's spells, line up stuns and buffs, and generally stack your builds so they feed into each other. The game rewards actually working together rather than each person doing their own thing.
Since the worlds and ability offerings are randomized, every group session ends up with its own shape. One run you might lean on Lightning and Wind, the next on Decay and Void, and the abilities your friends pick change what makes sense for you to take. Sessions are long enough to settle into — a full playthrough runs about 90 minutes — and there is recovery for disconnected or unfinished sessions in both single and multiplayer, so a dropped connection does not necessarily throw the run away.
Arena Survivors and what to know before starting
Patch 1.2 added Arena Survivors, a separate mode that keeps the same ability system but drops you into a battle arena with randomized waves that ramp up in difficulty. Progression is fast, a successful attempt takes around 30 minutes, and there are four arenas with their own layouts, hazards, and challenges. It is a good way to test abilities and builds without committing to a full 90-minute run.
Before you start, know that this is a skill-based game with a lot of systems behind it: 10 worlds, over 50 levels, 99 ability upgrades, randomized event challenges, and 4 multi-tier endgame challenge modes with 3 options each. The soundtrack is 7 dynamic tracks that shift with the run plus 10 tracks in the Temple hub world. Expect to fail runs early while you learn, and expect the permanent enhancements to make the later attempts feel different from the first.