Seth - sorry I'm away on holiday in Europe so I'm not getting much Internet access (but I'm nursing a cold and tooth ache in Madrid at the moment so I logged on!)
Yes, I have found that most OpenGL/SDL games work just fine on my core. The only issues I have had really are 1) with sound, sometimes it just doesn't work or crackles badly and cuts out. 2) leaving a game that has a different screen resolution than LMCE is configured for often screws up the screen size in LMCE
For the first one, I believe this is a more general issue as I have similar crackling sound when I login to KDE Desktop and the intro sound plays. Others have had this as well. Don't know how to fix this, and it wouldn't be high on the devs list as it doesn't effect sound in LMCE itself. But I note that it does only seem to effect certain types of games - particularly one game engine that is used for many different games. Can't remember which one but you can find it in some of my previous posts.
The second one, I just override the game resolution (in the settings files or with shell command options) to match my LMCE resolution (1080p) and then switching back doesn't cause a drama
As Thom said, you can then add the games to the computing menu by following the wiki article on how to determine the window class, etc.
Just to note, extending full LMCE support to other games (meaning removing them from the computing menu and making them a media type) is not likely to happen generally across all games. Thoms mame extension is all about the emulator, and being able to move the emulator and state between MDs.
Each of these games you are talking about may use a common or similar gaming engine which is broadly analoguous to the mame emulator, but they each come with their own instance of the engine rather than relying on a shared one - and you would have to provide a modified shared one so that you could do all the "moving" between MDs and integration with LMCE. I agree it would be great, but I'm sure Thom has plenty of other things on his plate at the moment! For now, the computing menu works well (although I know Thom hates it
)
Nexuiz works as well, btw.
On the MD questions.... they are full LMCE/Linux boxes so functionally they will run the games the same. But be conscious of the diskless angle. I believe that most of these games load all their textures and data, etc into memory before starting, so this may not be an issue. But if they start wanting to slave data from the core it will slow the game right down. So bottom line is, if it is going to work well, then heaps of RAM for the MDs as well... but that's cheap!