I plan on using delta_time, or variable timing to base the mechanics on. Right now its based on FPS. I'm worried that performance might be inconsistent across different players.
Oh, yeah. Definitely use dt for any performance-based game. I'd say the only time FPS is the better option is in a combat game where inputs are primarily focused on visual cues. Even good computers can sometimes drop frames, and in a precision platformer game, even dropping 1 frame can destroy a setup, depending on the difficulty of the trick. : )