The time rift mechanic is nice but the controls aren't very good. For me, the ground pound doesn't work unless I hold the down key. Using the ground pound to open elevators doesn't work well because there is a chance that it creates a time rift instead of opening the elevator. I would have preferred if the ground pound and open elevator were bound to a separate key.
Some sections of the levels are quite narrow which makes it hard to platform around as well.