I have this very vague memory of what I think is a Halloween-themed movie/short from the late 80's/early 90's. I remember renting it on VHS a long time ago. Searching keywords usually turns up with The Halloween Tree (1993) and after watching this, I don't think this is it. All I can remember is that it's about a boy who becomes ghostly/evil somehow (it seems like it was a gradual transformation). I don't remember anything about other kids like in The Halloween Tree.

The one visual memory I have is of a boy walking alone at night from left to right of the screen, on a sidewalk (I think alongside urban buildings) and climbing up one (perhaps an apartment?) into his window.

I got all excited when I heard about The Halloween Tree because it seems so similar but I don't think that's quite it.

It doesn't seem like it was a full-length feature... any ideas?

Thanks. This has been haunting me for years.

Sounds more like a video game from Apogee. Like Commander Keen or Duke Nuk'em.

I've still got one somewhere where the character walks left to right, climbs buildings, goes into windows... etc.

Just a thought

No, it's not a game. Speaking of, though, I recently discovered an old game I had been looking for, which happens to be from Apogee: Word Rescue.

It's definitely an animation, not a video game.