The first room. I built the surface cave part of the fall but didn’t screenshot.
Flowey’s first appearance.
The room with the 1st save point of the game.
The first puzzle room (solved by Toriel). The spruce signs on andesite are supposed to replicate stone plates with engraved text because Minecraft still doesn’t have stone signs.
I added a lot of lanterns because it was really dark without them. This made me realize there are no lamps or anything in UT and there's no sunlight, so theoretically it should be really dark.
The lever room. I put light sources under every appearance of water. The yellow “use this lever” arrows are in glowing item frames, again, for additional light.
The Tutorial Dummy.
The Very Literal Handholding room. The solution is additionally underwater - the light sources under the safe passage are a different color than the rest. You can’t see it though.
The test of independence. It’s the last room I made (for now), so this post ends here.