Thanks for playing my small project. This is not a bug: if you could move while carrying a firefly you could walk all the way to the goal without any challenge. I wanted players to consider how to best use their candles and available fireflies.
I've been trying to solve a level previewing problem and while doing that I forgot to reset the candle spawning script! LOL. Thanks again for the comments. I've also updated the instructions now to show how to throw the fireflies.