Speaking of, I've been working on a project that is ground up and is got quite a ways to go before it could really being a game.
Sounds intriguing!
Mind, I'm having to pick up a huge amount of knowledge. I think I spent three days just on stencil masks. And it wasn't even that important, I was just super annoyed that edge highlighting is typically a post-processing effect and didn't want to and that the standard methods (scaling the model up) were imprecise. None the less I found a solution. A 165 line, two-pass, stenciled geometry fragment shader (posted
over here, as it was the top google result for that particular question). There's an example in the comment reply stack.
All I've got at the moment is about a fifth of a half-decent map generator. It's missing a ton of small detail work and actual scenario elements, and its not hugely varied (how many rectangular rooms connected by fixed-width hallways can you really traverse before growing bored). Soooo...I've kind of got some impetus to scrap it and start over. On the upside, its better than my prior attempt, which ended up feeling cramped and overly large at the same time (no room to maneuver with really long travel times).
I'm also not as thrilled with my combat model (damage and weapons, actually) due to a conceptual mismatch between planned effects and mechanical and fluff description. E.g. 6 stats which can all be independently damaged with a variety of effects from turning the smartest robot guards into mindless imbeciles incapable of tracking you (as they keep forgetting you're a threat) to restricting vision range, movement speed, or damage output. Buuuut....I don't have good names for the damage types that make sense to effect enemies in these ways that also make for good mechanics that allow for a diversity of weapon types.
The goal was to make "raw damage" not a truly viable choice ("sure, you can, and it'll work, but it's not that interesting") and instead give alternatives that let the stealth aspect
work. Bean the guard over the head and he forgets about you as you melt back into the shadows (hooray, concussion!). Blind the watcher, sure he might raise an alarm, but he doesn't
know where you are so it doesn't do a whole lot of good. That kind of thing instead of just "kill everyone." Plus, I'm very much a fan of stealth games where getting spotted and having to get into combat isn't an instant-loss scenario. Deus Ex: Human Revolution felt like this most of the time. Styx Master of Shadows has its moments, but I feel that the combat is too brutal to warrant doing often (you can take one guy and get away with no damage about a third of the time, another third you just die; if you get
two guys on you you're just dead, you can't parry both of their attacks and parries are the
only option unless you get the slip on a guy: you parry and get an opportunity to counter-attack, hug it up and you get stabbed for a good 40% of your hit points). Which means that you're either killing everyone (if you have the opportunity to sneak up and insta-dead a guy, you take it, because that means he can sneak up on
you while you're trying to get around the next guard). I'm still kind of annoyed that the only way I got past one room of guards I had to use my 6 second-invisibility skill and run like hell and climb a wall where they couldn't follow. I tried so hard to sneak in and kill them one by one and it never worked.
...that ended up being a longer post that went into more detail than I'd originally intended. TL;DR I'm disappointed in parts of my original design or implementation and have a lot of things I need to still figure out and/or learn, but I've had a blast doing it.