Oh he loved that
It's a fuzzbutts mini stack a fuzz. Now normally fleece hammocks or any hammocks are a bit risky - they can be chewed and have rings at the corner they can catch their feet in. But our robo was so not that well really and he didn't bother to chew things so I took the risk and kept an eye on him and it was fine - no chewing. But to get rid of the risk of the eyelet rings I used very thick sisal rope to hang it up with so the knot filled the eyelet rings up. It was hung very low, almost at floor level so he could get in and out easily.
The fuzzbutts ones are made very well so no loose stitching - but they do have a cloth label on one side which can be dangerous if chewed with loose cotton threads etc. So I snipped that off and carefully pulled out any loose cotton threads left behind where it had been snipped off.
His main house is the wood one - he loved that too - I had to make a slope down to the entrance so he could still walk on the flat.
In his case he had a very large lump that affected his mobility. The hemp mat worked really well. You can also see easily if a bit has been peed on and just replace that little piece
How old is he? Our syrian started to drag his back legs a bit when he was quite old and it wasn't a spinal injury - they can get back leg weakness for other reasons.
If it's for a dwarf hamster then definitely keep everything at floor level,no shelves etc. I bet he'd like a labyrinth house as well though - and it will fill some of the space at floor level and the roof provides a very low level (like the house roof above)