I thnk that these two ideas could be a lot of fun for the game, and I do not think they have been suggested before (maybe in a much earlier post)
For an updated story mode, or as an upgrade itself, I think adding allies to the game could be very interesting. Of course, enemy armies would have to be sizable as the player him/herself already does tons of damage to enemy robots. The allied robots could be the same color as the player, and would probably be low-tier combat robots (the AI targeting system might have to be redone, as the enemies right will just track their single target, and multiple targets may confuse them). I just think charging out as a human robot with multiple allies on your side sprinting towards the enemy with you would be awesome.
When you or an enemy gets knocked down due to pesky spider grenades, you can roll to one side or the other. I think hat this feature should be an upgrade as well, at the cost of maybe half of an energy bar. This could be very useful to escape mk 3 hammer swings, and would allow the player to have more mobility.