I've mentioned the moving blocks thing before; a screenshot of that:
When coming through the Entrance Warp Door, there's no way back up from the Entrance save point, at least, not that I know of. This only applies the first time, though.
The Laboratory spikes are
very harmless. This is known already, but a screenshot helps anyway.
I'd consider giving them names, but that'd just be ridiculous and stuff.
Oh, and what's those spinning things?