Really cool! Amazing what you've done in this amount of time! It's fun and it works well!
I only think it gets a little repetitive to do the same levels over and over to repair systems, but at the same time it's nice to know exactly where to go. I think this was just the right amount of time for this.
Also, some levels are really hard (the piston and gear rooms) and doing the gears as my first level was a bit of a rough introduction xD maybe limit the first day to only 1-2 steps and make those levels in reach easy to ease in the player a bit.
Also also, some checkpoints would be nice, I died just before the exit a few times and having to redo most of the level is a bit annoying.
Those are really nitpicks though! I really enjoyed it and got an 85% S rank :D