Post surgery play ideas?

Our boy (2) has just had abdominal surgery. He is now on a strict exercise restriction for the next 3-4 weeks. Absolutely no jumping, no stairs and no toys, he has to be secluded from his brother in a small room with no places to jump to (my partner and I have split time so they both have someone with them!). We are 4 days post op and he is bored!! I would be grateful for any suggestions to keep him entertained. We have a fake fish he likes to watch and play with in water and a treat puzzle enrichment toy. Any suggestions of any additional enrichment toys that won’t encourage him to jump around? Any recommendations revolving around food would be great as we need him to put some weight back on!

Thank you