Nice game, I enjoyed it thoroughly. At the last and (somewhat less so) the second to last level, the difficulty shot up immensely though, and the jumping that's a bit iffy at times (sometimes, mainly on edges and especially if you're standing ON a laser that's pointing sideways, your jump doesn't go off) didn't make it any less stressful. But besides the those, there's overall a good introduction of mechanics and rise of difficulty throughout the levels.
Maybe adding a bit more story would be a nice way to spruce up the now somewhat overdone portal-esque experiment theme.
Also the physics/inertia, especially on the boxes and in the gravity-reversers, was sometimes a bit annoying to deal with. I had more than one box drop down from a ledge towards a button, only to slide off it, forcing me to restart the level in some cases.
One thing you can really improve on is your spelling/grammar. Three of the achievements have blaring spelling mistakes in them for instance.