(Yeah, kinda like that!)
At the moment, I am leaning toward allowing "changed" humans as a playable race, but not using every mutation on the Mutant Future list. Here's where my version is at right now:
THE CHANGED (MUTANT)
- Attacks/HD/XP/Saves as Halfling. Also, level caps at 8th.
- Start with 2 random mutations at 1st level. Drawbacks are part of same tables.
- The Changed gain a new mutation at 3rd, 5th, and 8th levels.
- Save at -4 vs. mutating energies.
- The Changed suffer a reaction penalty of 4 when dealing with any other race (NPC or monster).
The player can choose to be a changed animal, human, or plant. Changed are assumed to be at least halfling-sized (but no larger than human), of human range intelligence, and capable of speech (though perhaps having some difficulty articulating certain sounds depending on the shape of their mouths). Changed humans or animals roll once on the physical and once on the mental charts at the start of play. Changed plants are also assumed to be mobile. At start of play, mutated plants roll once on the plant and once on the mental mutations.
When a changed PC gains a new mutation (i.e. at 3rd level, etc.), the player rolls a die. An odd result means they gain a mental mutation, even means they roll on the physical (or plant) table.
I realize the above makes for an extremely random PC, but I figure that's sort of the point when playing a mutant!
I'm still on the fence about the MetalMen (androids). The version I came up with used Elf progression for XP, saves and to hits (with the 10th level cap). PC Metalmen are humanoid constructs whose AI has developed self-awareness and free will (to a degree). Their background programming causes them to tend toward Lawful alignment. They do not sleep (magical Sleep doesn't work), are immune to most normal poisons and diseases.
Androids start with a fixed number of hit points (probably 50), but cannot be healed (magically or otherwise), they must be repaired or repair themselves (self-repair rate is 1d3 per day, assuming it has at least 8 hours to work on themselves and basic equipment, which most androids have built-in or on their "person" by default). More elaborate repair kits and facilities exist, but are like Healing Potions, with limited supplies/doses. If an android is "killed", it cannot be raised, resurrected, or reincarnated. Only direct divine intervention or a Wish can bring it back.
Androids have an affinity for hi-tech artifacts, and can figure out how to use such objects with relative ease. Androids gain a +20% to Technology rolls.
We shall see. Perhaps they should stay NPC-only.