This was pretty addictive, I found the gems far later.
It seems like the map is procedural generated? Very simple, direct and straight forward.
The blinking bar as hint that you need something to survive works really well as a visual cue. I think maybe to make it more oblivious the mushroom could start off by saying "I need some mushrooms now, I don't want to die" or something along the lines to prompt the user to move because on the first play I was still orientating myself.
I hope you continue working on this to put in more obstacles / items to encourage the user to keep going further for a possiblity of a higher "game score". Great job on this.