Here is the full list of all 24 Plain Sight achievements.
Buy all 3 Mega Perks in a single round
Kill an opponent with a meltdown
Kill 4 opponents with a single meltdown
Buy any Mega Perk
Repel an attack with your own attack
Catch a falling star
Kill an opponent who is attacking someone else
Kill an opponent who has been repelled
Kill an opponent preparing to Meltdown
Block a meltdown
Travel 1000 miles in the air
Kill a jammed opponent
Capture 50 flags
Return 50 stolen flags
Capture a flag, return a Flag and kill an opponent with a meltdown all in one CTF match
Land the killing blow on Botzilla
Tag a Lighten Up object at max energy with 5 seconds to go
Reach maximum energy and detonate without killing anyone
At maximum energy, kill a stealthed robot using a flame sword
Get 5 or more simultaneous attack warnings
Tag an object in lighten up that has already been tagged
Kill 5 opponents while under the effect of a single Stealth Powerup
Kill 5 opponents while under the effect of a single Flame Sword Powerup
Use your shield to defend someone other than yourself