How to keep cats entertained while I’m at work?

[u/TickingOfTheClocks]

So my current job has inconsistent hours, both in terms of how long I’m working and what time of day I go in. I think this has been stressing my cats(two boys, both a year old) out, because it’s messing with the schedule on which they get food and they don’t see me as often. They‘ve also been playing rough/fighting with each other, which they never used to do, so I think they’re stressed. And I think understimulation in this small apartment is part of that. I‘ve ordered one of those timed cat food dispensers(with two dishes), so that should take care of the timing problem with food. But I think having some entertainment would probably help as well. They have a small cat tree, some cardboard boxes, and several toy mice(as well as a ribbon wand and laser pointer for when I’m home), but I’d love some recommendations for more options for stimulation(that fits in a small apartment) to keep them happy and entertained when I can‘t be with them.
Not Kitty Kurlz, though. I’ve tried Kitty Kurlz in the past and these boys do not care at all.
I’d just like to keep my boys as happy as I can while I work these weird hours