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