how long is this game in total in multiplayer?

[Kermie]

title

[Spectral_Orion]

There are over 20 levels available. As for the amount of time it takes to clear the whole game in multiplayer, it depends on your lobby leader's chosen difficulty level and how long it takes the whole group to figure out the objectives and achieve them. It can maybe take a couple of hours. Or longer if you struggle completing certain levels.

[starlitbows]

took my friend and i several weeks to complete the early access game in coop. but it was a lot of fun figuring out as a two person team and i can imagine it can be beaten faster with a bigger group.

[Terran]

I beat it in one day with 3 friends, on Normal difficulty, in about 5 hours and 40 minutes.
We went in blind.

[DirtL [天]]

Honestly it depends. I'mplaying on normal with friends, 8 hours in *blind*, and we finished 9 rooms... We used in-game proximity chat, didn't use in-game chat or any other forms of communication to make it harder and fun. If someone died nobody would know unless someone found a corpse. Unless you somehow speedrun the game I doubt you'll beat it in one day. I guess it will take around a week playing 2-3 hours every day, but it also depends on how fast you or your friends find exits/secrets. If you plan on having fun you won't beat it in one day trust me.