I see the potential as a self-contained game kit in of this type, but it has a looooooong way to go to be anything substantial. It also appeals to a niche group that is possibly dying out. I honestly though I'd be able to get into it, but I didn't even like games in that style when I was younger. My first FPS was Halflife anyway, and I've never played Wolfenstein, Doom, Duke Nuken 3D, or any of those.
I could literally write a thesis on what the developer could or should do with this engine, but what would be the point? Nothing has been updated in like 5-6 years or more, not even sure. Also, working with it makes me want to fire up Halflife and map something, but I JUST got back from an incredibly stressful California adventure and I do have to prioritize my projects for pretty much the rest of the year.
This has been a weird experience for me. I would certainly encourage anyone else to try it. It's not bad, but it's not good. It's simply a tricky canvas if you want a challenge.
I kinda tried. It's really clunky. It would take more effort than I currently have to give to make something impressive.