I think the 'vector' at FFFFE might just be some kind of checksum of the rest of the data, I likewise couldn't connect it with anywhere that looked like 'code' structures.
6502 is interesting, because none of the original games that run on it used a 6502, so I guess they're all rewrites then.
the blocks look game specific, so it might be you found the entry point to one of the games, not the menu
I couldn't see strings for several of the games in there (although it's possible they used gfx or a different encoding) but that did make me wonder if there was data missing.
Without a boot vector anywhere it does seem more likely it's booting from an internal rom, or some other device, or there is missing data.
