Fucks sake.
>>96800763
>>96801163
The two most popular mecha anime to set the dramatic, adult-oriented genre standard are Mobile Suit Gundam and SDF Macross. Before then, the genre was almost exclusively shounen: power of friendship, transforming robots, fighting aliens, the good guys always win in the end, etc, etc. Gundam especially pioneered the adult mecha series as a gritty war drama, depicting the loss, anguish, cruelty, brotherhood, stress, and fear of soldiers. It showed dramatic characterization in addition to the mecha themselves acting as a sort of second, sidereal cast and many times the characters' development is directly broadcast through changes to the mech. To ignore or downplay the mecha themselves is to say that you want a game with wizards, but magic should be "over there."
The reason mecha resonates with military and gearheads is because one of the key inspirations for type and role development, especially in Gundam, was the rapid development of combat vehicles throughout WW2. Granted, Bandai almost canned MSG until Tomino agreed to have new mobile suits almost every week, to sell model kits. The teams response was to have lines of in-universe development between units. The GM leads to the GM-II, the Jegan, the RGM. The Zaku II leads to the Zaku II, Hizack, the Zaku III, etc. As they fill both roles, you have much of the design influence of tank development as much as you do fighter aircraft.
A mecha character is an ace pilot...his mech is his life, his career, his best friend, his greatest challenge, and the best configuration of available combat technology he can get his hands on. That NEEDS to be represented or your game will fall flat.