Nice puzzle game, well worth playing. I finished in 2 sessions, but it would have been 1 if I hadn't been interrupted. The puzzle elements were introduced well and with a reasonable difficulty curve. I never felt board or out of my depth. The second secret level, with it's introduction of two new mechanics was challenging, but with it's limited scope, served well enough for an introduction.
Minor bug report for linux: after setting up my gamepad the screensaver would trigger, as there was no input from the keyboard or mouse.