Countdown is based off one of the gamemodes in Splitgate. This game is pretty simplistic but can have some strategy to it.
Countdown is a team based brawl that can host any number of players. Upon death it takes 5s to respawn, then you are teleported to the closest ally. Every death afterwards it takes another 5s to respawn. If you can have everybody on the enemy team dead at the same time, you win the round. Win three rounds to win the game.
This gamemode can be played with bots added in the lobby, but the game must be restarted every round because they bug out and will not spawn.