Fun game, will be awesome with music/SFX! A few things: it'd be nice to not hold down LMB at all times, I experienced noticeable lag between my mouse input and the light movement, objects should spawn well off-screen instead of on screen. Also, it can be hard to distinguish energy blocks from obstacles when they were close together, but I take it that's part of the challenge (just make sure they don't overlap!). I like the amount of progression, but it could be a tad slower; it goes from quite easy to nearly impossible in about a minute. Got to 1210!