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