A simple online multiplayer game about aliens trying to abduct you.
The “aliens” could be just a “dumb” computer opponent => just a beam of light shining down from the heavens. Or it could be OTHER PLAYERS.
The players must hide below buildings and trees to make sure they are not caught in the beam.
You have to recharge your energy/weapons/whatever, so you can’t stand still and stay in the same place. You have to make yourself vulnerable regularly to go out and grab stuff.
Crucially, the beam lifts you up, so it is also the ONLY WAY to get to higher places. You have to actually use the alien’s light beams, then make sure you get out of the area in time to drop off. (Or they’ll just catch you, of course, and you lose/die.)
This is such a cool push-and-pull movement mechanic, I should really use this for something.