Thanks, Virtuoso, glad you like her!
This is actually my first low-poly female character to attempt, but I’ll try to do my best. Also, as I’m now working all day during the week, I’ll probably only really have time on weekends to mess with her. Hopefully be able to get done during the challenge.
Anyway, let’s go into more detail as to the game for Sweet Tart.
As mentioned before, she’d be one of the crazy, psycho combatants in a “Twisted Metal” style arena combat game. You’d play it 3rd person and, with Sweet Tart on skates, anyway, it’d probably look kinda like Jet Set Radio Future or whatever that game was called except without the toon shading.
Arena’s would be big, and hide lots of different weapon pickups and power ups. To spice things up, there could also be a Mario Kart-style racing game types where you would attack fellow racers and try to finish first.
For weapons, you’ve got your primary and secondary. I think all the characters would have their own, unique secondary weapon (Sweet Tart’s Teddy Bombs, for example) and the primary weapon would change based on weapons found in the arena. And then, everyone would have some kind of bladed weapon, for when ammo runs out.
The other characters in the game would need to also have some mode of transportation other than just walking, but it would not be a vehicle game, so it’d have to be something like a jet pack or a scooter or something, so the action would be fast and furious. 
I want to play this game, now! lol