After a long period of time not collecting sufficient letters to spell word, enemies stop spawning

[pdpol]

I have only encountered this twice but will continue testing to see what might be causing it.

[nablam]

Yeah, I did get that .. no idea whats causing it but I feel like it's related to the boss's location and movement issues: sometimes the boss does not get spawned in the center of the screen (as he should) and since he moves left and right from his spawn point , he sometimes gets outside of the screen . Also sometimes, the boss never spawns...