If you want to help test, its available publically via the Steam Beta system, if you havent used it before, its available under the game's propertiies window -> Betas -> and select "sigma" branch

The game will update shortly afterward
*Warning* You cannot joint regular dedicated servers while on this branch, if you want to return to the regular branch you need to revisit this window again


Once you're on the sigma branch, launch the game and hit "Wave Survival" (name pending)
You can invite up to 7 other players to your lobby
Once ready, step onto the green platform.
The game will load the map, good luck!
Right now its only 4 waves, but its extremely challenging with 2 players. The more the merrier :)

If you have feedback, feel free to join our discord.
https://discord.gg/Efg8Cuz