I'm not sure if you want my opinion but in case you do me and a few associates have a few ideas.
1) I'm not sure if this is possible, but, make landing noises. Like, it makes a 'glunk' kind of sound when it hit's the ground.
2) Light mech; has 2 machine guns and jump-jets wow that was fast
3) Heavy mech; slower, more powerful nvm i didn't notice that it's done already