Yeah, both of those are bugs that I've fixed but can't update the game until the jam ends. There will be new stuff too.
The "block" with a candle next to the fire man is kind of like inverted so it lets you in but not out...sorry =P
Sounds actually gets paused if game window gets focus e.g getting back to game after alt+tabbing. If focus is lost sounds would be resumed but because game doesn't run while unfocused, you don't hear anything. I hope that's the case and not something else too?
You'll need both characters if you want to finish the game.