I don't think the difficulty is actually an issue in terms of the mechanics, I really liked each individual challenge/room. What I think DOES make it so challenging is the pacing. A lot of the time it's one really hard segment after another so there's no time to feel the sense of accomplishment or plan the next move. And again, I really enjoyed each individual part of the levels, I just think there needs to be a bit more leniency with the difficulty curve/spikes.

The force field mechanic is a pretty cool one, it adds a surprising amount of depth from such a simple mechanic. You also have a very nice variety in obstacles which is great too. 

This has a lot of potential! good stuff :)