Here is the full list of all 27 Super Sanctum TD achievements.
Kill 10.000 Walkers.
Kill the golden Walker.
Beat all levels on Hard.
Unlock all towers and skills.
Beat all levels on Normal.
Get all stars in all levels on Hard difficulty.
Clear Elysion
Kill the Patriarch.
Have no blocks at the end of a level.
Kill 10 enemies in a single Penentrator shot.
Clear Brightholme Industries.
Kill a Huge Walker.
Kill a Walker with an Anti Air Tower.
Kill the Charger and all its clones.
Clear the Hydro Islands.
Unlock all tower and skill slots.
Hit 10 enemies with Thunderbolt.
Clear the Facility Compound
Complete a level without using any skills.
Beat a wave with only skills and blocks.
Kill 10 enemies with a single shot
Beat a level on Hard.
Get 100 perfect rounds.
Kill a Big Walker.
Complete one level.
Clear the Training Area.
Kill 2 enemies with a single Bomb.