Im not sure why i went so blank on these questions, i mean the VN is fine. I suppose i don't really feel one way or the other on it. The writing isn't bad, the world is explained well so we know as much as the MC does. The characters are fine i guess, we haven't had enough time to really get to know them more than standard character archetypes. The only thing that drags me out is that the ferals seem really pointless. I know what your going for the whole mech battles but the 'feral mode'is really redundent and even the bi-ped ferals would probably just get out preformed by standard mobile heavy weapon platforms. If the convoys was escorted by even just 2 missile or simple rocket battery platforms any ico attacks would be blown appart as soon as they surfaced.
But getting back to the 'feral mode' issue. There's almost no use to using it in a combat scenario. The I.C.O have proven to rip through the feral units like paper so disarming yourself, losing all of your range advantage forcing yourself in to close combat with somthing that could destroy you in one hit doesn't make sence at all. The 'feral modes' one advantage is it would allow higher mobility which would be useful outside of combat but in combat any ranged ability would be vastly superior.
The combat being a main thing in I.C.O its rather noticeable when somthing like that wouldn't work or have a reason. The I.C.Os are shown to be incredibly powerful ripping apart ferals in the blink of a eye, so getting close to any of them would be a death sentence and rather pointless tactically. Risking a valuable pilot's life and the resources of a feral since their size and constant maintenance would be a huge investment to the limited and fractured economy of the craters. As a whole there would be no in universe reason to ever do it.
If you look at other mech universes they normally account for this even without explaining it. Code geass for instance first use the mechs agility to out maneuver normal weapons since that was what they was designed for. However when fighting other mechs they introduce shields that can block almost all ranged weapons so the characters are forced into using swords and melee combat. 'Feral mode' doesn't have such a reason its just sort of there.
I do get what your going for in gundem you have bi-ped mechs that can turn into planes and such but even then it for mobility mainly and they dont loose their ranged capabilities so they aren't sacrificing anything really. Ferals changing to all fours loose everything and don't gain much advantage.
This could be fixed if the 'feral mode' just had it own unique combat abilities like hidden missiles in the shoulders or a gauss rifle hidden in the mouth or on the back so it being on all fours would provide more stability and limit any recoil. Just things that would benefit or warrent it, but having it be exactly like an animal with just teeth and claws, well there's a reason why humanity ended on top of the food chain.
While typing this i got lost im my rambling so i've probably missed somthing or forgoten somthing, i dont actually remember what point i was making but i think whats here should be enough? Im not sure what im trying to achieve right now but oh well, hope this rambling mess helps somewhat.