Meh... why have the integration unless you have integration? I'd rather make one game capable of all that, and do it properly. The few genre-mixing games I've played (Battlezone 1 & 2, mainly, although I'd count Hostile Waters in there too, and I'm sure there's something obvious I'm forgetting to mention) were quite fun to play, and benefitted more from the integration than they lost in not being specialized. And FPSes are commonly including "vehicular mode" or however they term it, let's not forget.
While we're on the subject, here's a few games I'd love
to see as mash-ups:
- SimCity 4 and Midtown Madness (or SC4 and GTA2?) - this was done decades ago both in Streets of SimCity and in SimCopter, but not very well.
- Freespace & a Voyager Elite Force-esque FPS
- X-Wing / TIE Fighter & Jedi Knight
- Ground Control 2, Battlezone, & FarCry
- A 4X game (MOO, GalCiv2) & various kinds of space sims, from trading to combat to MMORPGs.
Basically there's 2 kinds of game mash-ups I'd like to see. The logical ones, where you can hop into a fighter, fly off to the enemy capship, board, and race through the corridors (already done to a minimal extent in SW Battlefront 2) - basically, encompassing the entire realm of likely actions a soldier would take. The other kind would be the creative kind (like the SC4 & MM2 combo), where you're not playing any one role, but instead, using something you create in one game style (city building, galactic-empire building) for another purpose entirely (racing, GTAing, corporation-building).