Here is the full list of all 27 Yet Another Zombie Defense HD achievements worth 1,000 gamerscore.
Survive night 7 or higher using chainsaw only
Survive night 9 or higher using mines only
Survive 6 nights without buying anything
Score 500,000 points in defense mode
Build and equip four turrets
Score 250,000 points in defense mode
Use no more than 6 clips during the first night
Play through a deathmatch game
Score 150,000 points in defense mode
Score 80,000 points in defense mode
Score 30,000 points in defense mode
Score 10,000 points in defense mode
Survive 10 nights without any barricades, turrets or mines
Survive 10 nights without taking any damage
Kill 8 zombies with a single sniper rifle bullet in defense mode
Kill 8 zombies with a single rocket in defense mode
Kill 300 zombies with shotgun in a single game in defense mode
Score 1,000,000 points in defense mode
Survive for 2:00 in endless night mode
Survive for 3:30 in endless night mode
Survive for 5:00 in endless night mode
Kill a reaper
Survive night 7 or higher using grenades only
Kill 70 enemies with flamethrower in one night in defense mode
Have 25 enemies frozen at the same time in defense mode
Kill 15 enemies with a single laser beam
Abandon all hope ye who enter here