Co-op roguelikes are chaos with strangers and perfection with a team. Find players who know the synergies, share items, and don't rage quit on floor 3.
Roguelikes with co-op are exponentially more fun with coordinated builds. Random teammates pick the same items, fight over upgrades, and die. A real team synergizes.
Hades, Risk of Rain 2, Noita, Dead Cells, Slay the Spire (with mods), and more.
Yes, completely free.