The problem is mechas go two paths always

>Path A
The mechs are fully customizable, but have no personality of their own by being completely interchangeable.
>Path B
The plot is focused so much on the pilots that the mechs are just there. The mechs may be well designed extensions of the character, but they are glorified power armor.

Then there is secret path C, where you have extremely mechanized characters, but thats just making a robot game, even if they are as clunky as mechs.

Posting vidya sneks