A very good level.
Things I liked: Non-linearity of the level. It felt as if it was thoughfully planned, and not made just plonking down rooms of lasers one after the other. Interesting "recycling" of rooms by making the players revisit some, but not backtrack.
Nonexistence of plot. My view is that some levels don't need a plot. Get over it, plot-lovers.
Scenery, challenges etc were good and polished.
Things that can be improved: Although the tidy use of tilesets in the level is admirable, the whole design lacked originality and freshness. Although aesthetically please, the level did not create a feeling of newness. On the other hand, maybe that's not such a bad thing.
Things commendable: The changeable difficulty. Although I haven't played the easy version, I appreciate that you have worked on two versions of the level.
Akk ub akk, a very polished, well made, high quality and challenging level. Well done!