Thanks for the update!
The updates look really good, and I like the new vertical backgrounds, especially the Biolab one! The new sounds are also awesome! However, I'm not too sure about the Snow one, it doesn't seem like an ice cave like you suggested, and the background doesn't seem to go well with the terrain.
Got some single-use trap suggestions for Food, Biolab and Gore:
Food - a freezer, where a lemming enters it, and gets frozen by it. The freezer opens, showing the lemming frozen in ice, and no other lemmings can enter.
Biolab - I really like those containers where they show a lemming hooked up to wires inside green water. Perhaps such a trap would be a lemming accidentally walking into the container, the container closing, wires hooking up the lemming and then filling up with green water. This might be very hard to animate, though.
Gore - a monster, of a different color, simply eating the lemming, licking its lips and then sinking down into the ground.
Also, maybe add antisplat/splat pads to Cyberspace and Biolab? These objects have been extremely underused and only appear in the Wasteland tileset.
Every tileset by other people released so far has had pickup skills, so it feels weird that the Sewer, Food, Snow and Gore have no such objects, and as such are in need of them. I love the custom designs of the pickup skills, though; they look very well-made, especially Cyberspace!