I think the only game I actually had fun building a ship was Spore, but building vehicles there is looks-ony, it doesn't have anything to do with function. I'm not a big fan of mechanical objects though. Mount breeding otoh is something I could get hugely enthused about in either an mmo or a single-player RPG. So I'll talk about that, I hope it's not too off-topic to what you wanted. FF7 and Dofus are the only games I've actually bred a mount in, and I didn't care for either system much. I've played several games that had cool pet breeding systems but then did not allow you to ride the pets: Celebrity Pedigree, Fish Tycoon, and the monster-building part of Spore are the closest to what I would do. A Tale In The Desert has a particularly cool system for genetically determining appearance (of scarab beetles) but it's more complicated that I find really necessary for a system to be fun, and I don't like the other aspects of the system (can't precisely control which 2 beetles breed, they breed when you aren't looking, etc.)
But here's what I think would be an ideal mount breeding system (assuming a 3D game, it would have to be adjusted to work with 2D graphics):
- Wild "mounts" (not rideable) are regular monsters in the game, captured in combat or found as an egg loot from combat with that monster.
- All monsters in the game are built from a standard set of parts (kind of like the parts library in spore, but the individual parts would not be adjustable, and would all be built on a 4-legs, 2-wings frame including a standard point where the human avatar is attached in riding mode. (Pairs of legs or wings could be left off to get animals with fewer limbs, such as snakes. Humanoid monsters, if any, would not be available as mounts.
- Wild "mounts" would be tamed or raised to adulthood with some kind minigame interaction. Then each would be breedable X times before it "expired" (escaped back to the wild).
- Bred mounts, once raised to adulthood, would be rideable and breedable an infinite number of times. They could be traded/sold however traded ones would not be breedable.
- Appearances would be controlled genetically: 1 gene for body type, 1 for head type, 1 for leg type, 1 for wing type, 1 for tail type, 1 for mane/crest type, 1 for horn type, 1 for base color, 1 for accent color, 1 for the pattern of applying the accent color over the base color.
- Optionally mounts could have a stat or combat ability system, but the details of how that worked would depend on your intended use.
One other thought, I quite like the idea of living spaceships - I've seen a few sci-fi universes where "starships" are rather like dragons or whales except your ride inside instead of on their back (since their back is presumably out in the vacuum). A system where it was cheap and easy to breed mini versions of these, but had a big $ investment to grow them from their normal small size to working ship size, might make for a good economic implementation.
Edited by sunandshadow, 21 June 2012 - 03:06 PM.