It's a kind of "side" mode in The Finals, which is an FPS game. In Power Shift, 2 teams of 5 try to push a floating platform from the center of the arena into their opponent's base, in a sort of reverse tug-of-war battle. As the platform traverses the arena, it effortlessly demolishes all structures in its path, so the destruction and chaos are cranked to 11.

It's sort of similar to "payload" type objectives in some other FPS games like Overwatch or TF2, but instead of teams taking turns, they're both pushing against each other with the same payload. It's a ton of fun!