I can see where the bug occurs. So apparently when you start the game, it tends to not respawn after you die. But after refreshing the page a few times it worked properly. It seems to be more apparent on the latest version of Firefox as I had no trouble with Chrome.
OTHERWISE! It's a step above your typical Flappy Bird clone. It's neat you have powerups and have to collect the triangles to get points instead of just dodging. The thing I would fix is to clean up the graphics such as the characters and font.
Also I don't know if this was intentional, but the sound seems to be low.