(a) should really be done anyway but probably not going to reduce the numbers that much
(b) I don't really like, likely to end in disagreements over exactly where something belongs - to pick something from PC games just as an example, does Football Manager belong in "sports", "strategy", etc.?
(c) maybe something as simple as "Games - # to L", "Games - M to Z". Possibly unbalanced, maybe makes for more work?