Honestly quite elated to receive such a lengthy response... thanks a lot for your time! I think I might have tried those other games you spoke of but certainly didn't get very far, I don't think they ran very well either, which sucks because I'm big on transformation in general but oh well what can you do.
You did answer my questions, yeah. Though learning that the goo (might) be a bioweapon does pose a bunch of interesting questions on its own. What would be its purpose, strategically speaking? If it's used for neutralizing personnel, how do its creators ensure it won't harm them when they move in to occupy the subdued territory (if I'm getting this right), considering it seems to grow and proliferate just fine on a relatively sterile environment such as a spaceship? How can they undo the biological conversion it does to other organisms to further their own goals (since if I recall correctly from the other games they assimilate organisms from other species)? Wouldn't the associated cost with cleaning up a goo-infested enviroment and population hamper its utility? Maybe even its creators don't understand it fully yet and it's just a prototype weapon?
A game where you control a monster that builds an army by impregnating others sounds like a banger idea. I've brainstormed a bunch of similar themes myself, but as I am currently extremely lacking in the skills required to make a game I've just had it as a sort of brainworm I feed every once in a while by working out the mechanics and setting before I tuck it away on some dark corner of my mind whenever I'm bored. I initially envisioned it as an RTS where you yourself control some sort of hive queen character capable of spawning multiple types of unit and some of them might have that capability, but looking back on it now I think it'd be better suited for an infection-type game a la Infectonator, also because it would be really fun just watching your guys overrun an entire population in real time. I don't know. Hopefully I can make that some day.