- Collisions (crashing did damage)
- Knockdowns (crashing could result in falling over and getting back up again)
- Destructible terrain (limited to 1 tree and a few traffic lights on River City)
- Working screens in the Mech cockpit (took up too much resources, was removed)
- Mech legs adjusting to terrain (adjusting the angle of feet and bending of the knees to stand directly on the surface). Also known as inverse kinematics.
- A 4th Centurion variant (CN9-AH)
- Repair and rearm (You actually had to pay for spent ammo and damaged mechs. Expensive equipment was more expensive to repair, Artemis missiles were more expensive to reload.)
- Mechs being able to move at 200 kph
- Collateral damage when mechs exploded.
- Glowing eyes on the Atlas
- Light mechs that could fly.
- Damage textures that reflected the type of damage that had been done (bullet holes for ballistics, melted armor for lasers, etc)
- A mech-lab where you could click any component on your paper doll or the mech itself to configure equipment in that component. E.g. click the right arm to modify the right arm.
- A "hangar" shortcut in the UI with 4 mechs of your own choosing, to easily swap between favourite mechs between battles. No searching through 100 different mechs in a long list with loading time.
- Better graphics
- Spiralling LRMs. They didn't just move in a straight line. (As seen here)
Funny jokes are welcome, but will not be included on the list

Edited by Nicolai Kabrinsky, 26 August 2014 - 10:51 AM.