Vulgus I got stuck with the game logic, couldn't really follow it. But an automated transcode would work.
Tutankham I did a very, very long time ago, and IIRC only enough to patch it to run on the CoCo3. The hardware is bitmapped graphics, so it wouldn't work on the Neo Geo. At least, not without a lot of changes to how things are done.
Mappy I like, Grobda I'm sure I've seen it but can't recall it off-hand. There is a 68K version of Mappy on Namco Classics Vol 1. Would love to dive into that one day and see how they've implemented the old games on it... I wonder whether they wrote C versions of the code???