This is a great start, keep at it! eduard0 Has some good points;
add keyboard navigation at "next level" screens,
add background music with mute,
more levels and a level selector.
Look foward to a follow up.

Needs improvements... here's a few thoughts:
-Increase the walking speed, it's painfully slow at the moment.
-There is no reason (at the moment) why player should press space when at a switch. Make the switches so that they are automatically activated when player touches them.
-Add keyboard navigation to the main menu and the "next level" screens so that the player doesn't need to unnecessarily move his/hers hand to the mouse between levels.
-Make harder levels. For example there could be switches that activate multiple blocks, and two different switches could operate one single block. Using this it's possible to increase the difficulty so that you can actually call this a puzzle instead of run through.
-Add background music (with mute and volume control options).
-Add a timer to the levels and a level selector. Maybe also a high score list is in place.
-Some enemies could also make it a little more interesting.

Hopefully we'll see another submission soon. :)

I was expecting another pointless game but this actually surprised me. The only thing I would really change would be to add more levels with steadily increasing difficulty. Although the game was very short and the mazes relatively easy, I still had more fun with it than I initially hoped for.

this is the best

huh