Here is the full list of all 41 Grenade Madness achievements.
Reach level 10
Try every active ability
Kill 1 enemy with Frag grenade
Kill 1 enemy with Sticky grenade
Play for 10 minutes
Heal yourself for 100 HP when you are near to death (less than 10HP)
Play for 800 minutes
Kill 100 enemies with Frag grenade
Reach level 200
Kill 1 enemy with Holy grenade
Kill 100 enemies with Sticky grenade
Reach level 150
Kill 1 enemy
Kill 100 enemies
Kill 500 enemies
Kill 1000 enemies
Kill 5000 enemies
Kill 10000 enemies
Kill 500 enemies with Sticky grenade
Kill 5000 enemies with Sticky grenade
Kill 500 enemies with Frag grenade
Kill 5000 enemies with Frag grenade
Kill 2 enemies with one grenade 100 times
Kill 3 enemies with one grenade 100 times
Kill 50 enemies with melee weapon
Kill an enemy when you're dead 100 times
Build 10 crates
Build 500 crates
Play for 100 minutes
Play for 3000 minutes
Win the game (first in ladder)
Win 160 games (first in ladder)
Kill 150 enemies with Holy grenade
Play every map
Collect all power-ups
Collect 100 power-ups in one game
Kill 40 enemies with active Ghost powerup
Use teleport 40x to kill enemy
Reach level 50
Reach level 100
Top Secret