Updated as I play some:
Greeble: Having to press "z" makes me dread keyboard issues (I am on qwertz). Fell into a dead-end pit and quit.
Lossst: Uses ALT for a crucial move, ALT triggers my browser's menu. Got stuck. Quit.
Lost Beacons: Works nicely but the scrolling is jarring and confusing. Would have played more than 2 levels otherwise. Sound would help tremendously in keeping a track of what is happening.
The Lost Packets: My clicks often don't register? Gave up on the second level.
Lost in a Space Odyssey: Cute, fun and interesting. Had lots of fun!
A moment lost in time: Some confusion with cursor capture. Interesting but seems more like art than game. Confusing.