Here is the full list of all 16 Tetradecagon achievements.
Die 5 times on one level without progression
Beat your highscore.
Lose control of the ball seconds immedietely after bouncing it.
Die for the first time.
Use the Konami Code.
Die 100 times.
Perform a 360 while bouncing the ball.
Perform a 540 while bouncing the ball.
Beat the highest level, Icosagon.
Beat your highscore 10 times.
Beat your highscore 50 times.
The illusion of allusion.
Suck 500 times.
Die immediately after the grace period on the first level.
Glitch the ball out of the polygon.
Enable epileptic friendly mode.