Stumble Guys

Here is a way to get the achievement in custom games

Go to the Main Menu of Stumble Guys.
At the top right of the screen select "party"
Select "Custom Game"
Keep Max Players at 32, and make sure "Fill open positions with AI" is checked
Rounds Set to 3.

For round one, press select, then to clear selections, then find "UFOMG!" and select it with . Then press to accept.

If you wish, select two other Levels you need for rounds 2 and 3 (it gets harder to advance each round). Then press to create the game lobby.

Then press again to play.

The AI Stumblers are very bad and this will be the easiest way to get it.

TIPS FOR THIS LEVEL:
This level greatly benefits from being round 1 as it is one of the hardest levels.
The middle section you spawn on goes away about 10 seconds into the level, but the sections on the very outside do not, if you stick up there you have a great shot at advancing as most AI will fall below.
If you do get knocked down, try to stay on the tiles but watch out as they fall a second after you touch them.