Honestly assets can be extracted from a lot of older games, the issue is usually licensing. Nightdive has a good writeup somewhere of the hoops they have gone

Honestly assets can be extracted from a lot of older games, the issue is usually licensing. Nightdive has a good writeup somewhere of the hoops they have gone through. They say it usually boils down to: "Mr Rights holder, can you license this property to us" "No I dont know if we own that property, we would need to check paper records and that costs money" "Ok, but then you wouldnt go out of your way to sue us if we did resurrect this old game" "No if we saw you making money from it we would definitely spend the money to figure out if we had a viable lawsuit"