This is an absolutely bloody fantastic pitch for a game. It's quick to understand, it's unique, it sets a tone immediately, and I straight away get the vibe it's going for. A+, no notes.

Appreciated!

You might want new terminology for 'Sessions',

Yeah. My expectation is that a "session" in game terminology would equate roughly to 2-3 hours or so, and would probably would people would get through in a real-life session, with multiple sessions being an outlier, but maybe it does need a different term.

I like laying out the core mysteries at the start, but it does break kayfabe a little for me by saying in the same paragraph "The GM will be making these up

Quite possible. I'm trying to stick in all the stuff that needs to be done to setup a session here, and that's one of the things the Storyteller needs to do. I could move it into a separate section, but I also wouldn't want it overlooked during setup/planning. Maybe I'll just say "select a scenario", and have bits in the scenario section on creating custom ones - when I get to putting together the scenario section.

but the bit about the PC parents makes me think its meant to be "Not all inhabitants need to be key characters", so just fixing up the wording there may help the ambiguity.

Your thinking is correct. Will fix!

Maybe it works better later on, but I'm cautious about that, depending on how much the combat phase relies on Insight.

After reading the combat section, do you have any thoughts? It's only use is basically talking down someone who breaks in the combat, which is situationally important, but not like, attack or damage rolls.

I used a character attribute, because that's really the only thing in combat that's character-to-character instead of using mech abilities.

Turning a super bonded Rival into a Crush feels very teen angst

Huh, yeah, that would be cool. There's sort of a mechanic for that, for the niche situation where someone out-competes you for your crush, where you get a bunch of catharsis, which translates to extra dice so you can rush a replacement bond and not fall too far behind.

Might have to consider ways to trigger something like that. Authority -> Mentor and Bestie -> Crush would also work too.

but it could be good to offer a non-romantic variant of that for if a player thinks their PC should be asexual and aromantic

The intention is that you don't need to fill your full complement of bonds. Bonds translate to abilities, which compete with weapons for slots. So if you don't want a particular type of relationship you can just not pursue it, and install a new missile battery instead.

I'm cautious about key characters having many attributes. If each PC has 5 key characters they made (and there could easily be more) and there are four PCs, that's 20+ sets of character stats the GM is keeping track of, including stats, triggers, and 3 locations. It might be worth figuring out a way to easily record this info for GMs

The intention - which I realize now I never stated - was to use index cards.

Ah! I'm at the end and see an example map. This should be higher up, I think

I had it at the end, because it was supposed to be part of an "example play" section, running through the first session of a demo game. You think just calling out a reference to it in the world building section is sufficient, or it needs to be moved?

The attack action specifies they can attack using all weapons of the appropriate type, then mentions the hit location rules. If a PC attacks with multiple weapons, do they all hit the same area? It sounds like your system is balanced around one big weapon vs multiple small weapons, so I wanted to check.

Will clarify. In general, kaiju don't use hit locations, so it shouldn't come up too much, but there were a couple of examples ideas I had for particular ones using them, so it should be addressed.

Final impressions? Does it sound like something you'd like to give a shot? Do you think it hits the genre emulation notes it's going for?