I like the concept. There's a nice ebb-and-flow to both sides of the gameplay.
It might do well to have time-stopping be a toggle rather than a hold — managing space, mouse and WASD was a bit much.
Most levels were easy to get through by sticking to one side of the screen. Although, I think Level 5 might be impossible. I went down without stopping time or hitting anything and 1200 is the most I can get before the end's 1500 goal.
Good work!