Here is the full list of all 24 Plain Sight achievements.
Kill a jammed opponent
Buy any Mega Perk
Kill an opponent who is attacking someone else
Land the killing blow on Botzilla
Kill an opponent preparing to Meltdown
Repel an attack with your own attack
Kill an opponent with a meltdown
Tag an object in lighten up that has already been tagged
Catch a falling star
Kill 4 opponents with a single meltdown
Buy all 3 Mega Perks in a single round
Kill an opponent who has been repelled
Block a meltdown
Travel 1000 miles in the air
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
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
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