Just to add. One thing they really do love is lots of substrate in the base of the cage - so they can have normal behaviours like burying hoards and pushing the substrate about or digging a bit. I thought from the photo your hammy looked quite low down in the cage. They need about 4" deep of substrate but most people try to put about 6" in (ie just below the edge of the base - any higher and it can spill out!). It might sound like a lot of substrate but - it lasts a lot longer the more you use - because then you don't need to do clean outs very often (especially if they use a potty tray!). You can just "spot clean" mostly and go 2 to 3 months before having to change the substrate - even then it's usually clean and dry at the bottom and I reuse about half the old substrate and mix it in with the new - that way it still smells familiar to the hamster, because it still has their scent, so it's less stressful for them. Big clean outs can be very stressful for them (if you didn't know already!). They scent mark their cage and leave scent trails in their substrate to help navigate their way round the cage (as they really don't see well) so if everything is cleaned at once they can feel a bit lost and stressed. So partial cleans are better
I do the wheel a different week from the substrate as well - and any other items, just as and when needed.
You might want to think about a bigger wheel for him as well! I can't see from the photo well, but it looks like a smaller size flying saucer. It can be an issue fitting a bigger wheel into the hamster heaven so some people remove one of the shelves (usually the one with the holes in) and put a bigger wheel at that side. Something like the 28cm Trixie wheel is really popular. The wheel that comes with the cage is a bit small and they can't run with a straight back in a small wheel. Goodness knows why manufacturers still put small wheels in cages!