Hello, I just finished a T3 run to the Clockwork Terminal. On my way there I found a danger room that wasn't listed on the Wiki. I was really hesitant to go in because I'm trying to heat all my 4* items up, but I thought I'd take a peak, hope for the best, and hope I could still get down to the terminal. Pleasantly it was just more jellies, and it was really easy. I died on accident from some unlucky knockback/shield break/spike strip before I could pop a capsule, but it was simple enough.
Here's the pictures, I forgot to take a shot of the 2nd wave. It isn't a completely 100% new room, it's a Cross Spike Design with respawning explosive blocks.
The danger room before the fighting starts:
http://cloud.steampowered.com/ugc/488876173304224768/ADEEE8E7C19A56A1DBE...
Wave 1 -- Consisting of only blast cubes
http://cloud.steampowered.com/ugc/488876173304223845/02EEDFEA717E9F26A6F...
Wave 2 -- (Forgot to take a picture) Consists of frost jellies and some lichens, enough to spawn a giant lichen and a medium one
Wave 3 -- Consisting of blast cubes and quicksilvers
http://cloud.steampowered.com/ugc/488876173304222894/3E6AECC1B7BB4EE1D99...
but I can't say I've fought that assortment of jellies in it before.