Non-flying subs would require some pathfinding to navigate (ah-ha) around landmasses. In terms of game, it would be a very radical change, for example America is a huge obstacle between Atlantic and Pacific. Also since the game interface has a limit of 6 bases, you'd have no more than 4 aquatic bases to patrol the entire world...
A big challenge would be for the game engine to handle (and distinguish) both bases facilities. It's an issue that's completely avoided by having different rulesets for the two different games.
Yeah. They are obstacles, but I think they're not only surmountable by the community (and especially our very talented coders), but also would provide more fun for the players. Your first base location is an important question; it would be even more complicated with a naval base. (The Pacific seems to be the obvious choice, but would you really abandon Europe and the Middle East?)
Why having a hybrid game?
The games share some similarity, but only to some extent. They are different. I'd rather play them one at a time than having a hybrid.
I fully understand. However, these "hybrid games" have been a recurring theme for 20 years, most prominently in the X-Com Util, and people played it. So I thought, if it exists, it should be made properly.
Hence my initial thoughts on how to merge not only the games' resources, but also their logic.
I would rather see them one after the other. Complete the first game then merge into TFTD with parts of UFO carried over. Start with soldiers from UFO or something like that.
Yes, but this actually creates some logical problems. See below:
TFTD is happening 40 years after UFO. Also, the Avenger that raided Cydonia, with your elite soldiers... it didn't come back. The desperate mission didn't account for a ticket back to Earth.
Even if it were true, what about the other ten Avengers you left back in your bases?
What about heavy plasma guns? Power suits? Blaster bombs? Even if some of these technologies won't work underwater, there are still land missions (terror). I know TFTD handwaved it by saying that there's no more Elerium to power these things, but it wouldn't apply to everything, for example Alien Alloys.
Yes, TFTD takes place 40 years later (I thought it was 60, but I'm not sure). And well, the T'leth arc would have to be moved much faster, to the first alien war, and somehow fitted into the plot. Still, these are technical issues, as many people simply want to play hybrid games and they will anyway, so, as I said, let's give them some way to do it properly, without too much suspension of disbelief.
Basically we would have to add elements from TFTD to the basic game, balance them properly (weapons, aliens) and think of a way to tie these stories together. I'm not a huge fan of hybrid games, but I still think it would be very interesting to say the least.