Added

CO-OP: team up with up to 3 friends in one shared arena, with the same waves and the same bosses

A special CO-OP button beside PLAY on the main menu

Host a lobby: choose 2 to 4 players, who can join (Public, Friends only or Private) and the run's mutators

Lobby browser: find open public co-op games, with search, a hide-full filter, player counts, mutators, status and ping

Lobby room: see who's in, pick your character, ready up and invite friends; the host starts the run and can remove players

Every co-op screen takes place in THE MASHED MUG, a tavern with a party board and Barkeep Buds behind the bar

In co-op everyone keeps their own character, starting weapon, upgrades and shop, while coins and XP are shared by the whole team

Crates in co-op belong to whoever walks over them and open in their shop

Downed players drift around as a ghost and get back up when the wave ends, and the run is over when the whole team is down

Between waves everyone readies up, and the next wave starts when the whole team is ready (or 90 seconds after the first player readies)

Teammates show their name and HP over their heads and in a team panel

After a co-op game over the host can take everyone back to the lobby for another run

Balance

The more players, the harder it gets: every extra player brings a whole extra horde, +25% enemy HP, +10% damage taken, much tougher bosses, an extra elite in every elite wave and weaker revives

The lobby room shows exactly what your team is in for before you start

Each player still earns about a solo run's coins and XP, and boss and golden potato rewards go to everyone in full