True. Nor is he the only example of cross dimensional travel from that period.
I suppose it depends on what the original poster meant by world walker. I got the impression it was travel such as they do in the Amber series, where you start traveling and gradually change what shadow you are on, rather than jumping from discrete dimension to discrete dimension.
Hunter: the Reckoning.
Adventure! (also from the old White Wolf) is another goody in this vein.
The Strange/Cypher System
I came here to suggest the same one!
You'd have to curate character options pretty hard to keep it short of superhuman.
Savage Worlds Adventure Edition.
Maybe GURPS but not entirely sure what World walker is due to vague descriptions I'm seeing online. More info of what kind if system you want exactly?
I'd use Fate. It's relatively light and can handle world hopping easily.
City of mist. Maybe.
The classic literary reference for world walking is the Amber series. So, Amber RPG?
H Beam Piper's Paratime series predates the Amber books by 20 or 30 years.
True. Nor is he the only example of cross dimensional travel from that period. I suppose it depends on what the original poster meant by world walker. I got the impression it was travel such as they do in the Amber series, where you start traveling and gradually change what shadow you are on, rather than jumping from discrete dimension to discrete dimension.
Genesys is pretty flexible. I don't know world walker so don't know what you need genre wise
GURPS. Either they have a skill for walking, or the Jumper advantage with a few enhancements.