Interesting, only the Super Famicom Zan games. There is one PC Engine CD Zan, however they would need to cross license with Taito which probably would raise the price significantly.

And I might add, there is an older build of Off the Wall that was dumped online. Not as complete as the one seen in the videos.

Marble Madness and Off the Wall seem to be pretty close to finished. One of the reasons at least those 2 never got released is because they debated about how to release them, with a special controller or just relying on, believe it or not, PC Engine mouse support.

Yeah I can't say I'm a fan of Pit Fighter but I'd still be curious to see how it turned out

Also, there was supposed to be both HuCard and CD versions of Pit Fighter. But so far I haven't seen any footage or pictures that give any indication of how far along those got.

Footage of several other PC Engine games by Tengen that were canceled can be found on the account of the director Jun Amanai. Marble Madness, Off the Wall, Peter Pack Rat & Popils. They were for sale, I'm not sure what happened with that.

youtube.com/@junamanai69...

I passed your results along to the dev. I haven't had a chance to try it out in emulation yet

Like others have said, depends on the genre. Overall you want to just give a person a feeling for what the game is about. Introducing an ability or two. Introducing how battles are played out. 3 or 4 music tracks max. I agree on cliffhangers.

This one has two patches that are available. One that's an English translation patch, and another that upgrades the graphics a bit. I haven't gotten around to trying them out myself but it sounds like the patches are compatible with each other.

Tengai Makyou 2 is allegedly in the works I think by SamIAm? Someone was looking into both Tenshi no Uta's, but haven't seen him online lately. Anearth Fantasy Stories has been fully hacked but is on the back burner. Emerald Dragon is gradually in the works as well.