Nicely done traditional roguelike! 

I played down to level 15 and threw a potion of acid gas at an ochre jelly. The game kind of 'locked up', the music kept playing and the idle of the character kept going, but the controls became unresponsive. The potion did not get thrown, it stuck in the prompt for throwing. Seems like a bug, maybe. Tried logging in again and was a fresh character on the overworld. This all happened in the web version, if that matters.

Thanks!

Hum, thanks for reporting this. I will investigate and try to fix it!

Same happened to me. Threw unknown potion at the thief rat (not sure what enemy called).

I think this bug will be solved on next update. @TimaWUB helped me to reproduce the bug and I found flag that Ive missed to reset when throwing a potion after cancelling an staff zap.