What impresses me most is the un-picolike feel and the big amount of content. Often, a PICO-8 game is just one (very good) idea blasted on screen and that's it but this game doses new content sparingly.
The lightsourcing makes the tomb feel quite claustophobic, it's a very cool way to make the puzzles and the rooms feel more urgent. It feels like it serves the game more than just makes it look good.
That said, I think the only trouble I have is with jumping over holes (and I guess a lot of that comes from the tiny resolution of the PICO-8) but the relaxed retry politics pretty much eliminates this problem. If you drop you just try the same screen again.
5/5, would loot again.