Thank you nikomaru! In fact, two big influences for me were Into the Breach (mech vs. kaiju PC strategy/puzzle game) and Knights of Sidonia, a rather bleak mecha manga drawn by Tsutomu Nihei. My sketch of a solar frame has a little influence from Sidonia's "Garde's".
The d8 for character creation is as-intended. This dice system is deliberately asymmetric, due mostly to the various ways that Burn/Vent and Shivering/Attracting differ.
The only way to unlock the rolling of d10s is by either having a Frame "well-disposed" to your challenge, or via the Reactor Burn mechanic, putting a clock on your reactor's survival if you undertake a lot of Hot actions and threatening Shivers against even the most hot-blooded protagonist.