Interesting arcade style game. Both times I played I lost because I cut too many "open" files, usually because a "secret" file was on the edge and a open one spawned while trying to cut it. While I find it a bit unfair to lose in that way, I don't think there's anything wrong with it the way it is.
While I do think it could do with a bit more substance, I'm not sure what else you could add. Maybe more types of files that do different things?