I'm glad you enjoyed the music and the game ^_^
You can fullscreen the game from the options menu but honestly I just noticed thanks to your comment that the default fullscreen button that normally shows on the bottom corner is nowhere to be found in our game, I must have messed it up when exporting the project >_<
About the explosions being too slow, it's definitely a valid point of criticism and we're looking forward to make a patch for the game after the jam that will fix that issue along several others like the movement not being very polished.
Thanks again for playing and for your feedback!