Technically, as far as the mechanical functionality of the map being in compliance with Gen, no. There are no special item/player spawns that differ from what works in vq3 and TA.
However, while constructing a map for Gen, there are gameplay elements to keep in mind, such as which item translates into what for each class, since item definitions get translated across classes when they're picked up. For example, when a Slipgater picks up a LG, they get the Shaft, along with the amount of cell ammo typically recieved upon that weapon pickup for Quake1.
The big translations I'd recommend keeping in mind would be the GL (and ammo), BFG ammo and the RG. GL spawns translate into a RL for Doom, and a Mortar for Earth. Keep in mind that there was no seperate grenade ammo in Quake1, and that the Slipgater's GL and RL share the same ammunition. An abundance of grenade ammo could easily empower a Slipgater into dominance. BFG ammo is a big cell pickup for Doom, Slipgate and Strogg and extra bullets for Earth, while merely being BFG-exclusive ammo for Arena. It's a good itee to have included in a map for Gen, but not for vq3 if there's no BFG on the level. The RG translates into the Sniper Rifle for Earth, CG for Doom, RG for Strogg and most importantly, the SNG for Slipgate, which is a weapon that requires about the same range as a shotgun and a huge stash of ammo in order to be effective (Dynamic translation, isn't it? =]). If there's a RG spawn in the level, please ensure there's also a RL or LG spawn as well, otherwise the Slipgater will not stand a chance.
If you're thinking about remixing or creating your own Doom map, please try to include the Medkit, which translates into the Beserk Pack pickup for Doom. Everyone surely remembers punching through hordes of demons back in the day, and doing the same with players is just as entertaining as well as nostalgic
One last note to remember is that each class has their own set of physics, so they all move around maps differently. Strogg can strafe-jump up slopes, Slipgate can turn on a dime (see my Slipgate Trickjumping thread for demonstrations
), Doom has a fast acceleration and normal running top speed, whereas Earth is all-around slower. It's OK to build in class-specific trickjumps to get to certain items and paths, so long as those same items/paths are reachable by all classes. If only the Slipgater can get the MH or RA due to being able to complete a U-jump, that's bad map balance for Gen. The 125fps extra height trickjump is fine as well, so long as there is a way to climb up the same (or a similar) route for players who don't have machines that can run that sort of framerate (or would like to enjoy the game rather than run the map at r_picmip 8 just to play well in it).
One final rule: Have some fun! That's what Generations is all about =]
p.s. If one of the other guys could build a nice matrix showing item translation (or give a link to one pre-built), that'd be helpful too =]
