Shockwave grenade that flings every player in direct-LOS with a force inversely proportional to distance.
Gravitic grenade that does the exact opposite.
Acid spraying alien that makes an area hurt Humans, similar to dead eggs/OM/hovel.
Tactical Nuke, built by ckit, takes 2 minutes until it finished arming, kills everything within 2500 units, and flings their bodies away at ludicrous speeds.