I love the role reversal here: you're not the runner, you're the gremlin level designer. Dropping shelves and pillows in place and then watching the traveler commit to it is such a good loop, and the ragdoll-like physics are hilarious.
Presentation-wise, it's super easy to read: the UI is clean, the drag/drop tools are straightforward, and the pause-to-tweak option is a really smart touch that lets you iterate without killing the pace. The chill vibe/music and simple visuals also fit the concept nicely. It feels like the kind of game that would be dangerously addictive with more levels.