Adding some descriptions would definitely make the game easier to start with. For example the game starts with the orbs that can be clicked without danger, this could be shown or described.

Also the boxes are not dangerous, and the walls are unknown in strength.

It could help to add 0 to non-dangerous items, to make this more aligned to the rest of the numbers, or a ? for the walls.

I also struggled to understand that i survive with 0 health.

Lastly it doesnt make sense to me why the killed monsters "gold" must be gathered (clicked again). I strongly assumed i cannot have more then the slots filled with gold, only when i had to pick one up i did so and figured out i can have + gold.

Apart from the difficult part of understanding how it works, its a very nice game. But you took quite some time off the reviews i have to do for my students game design projects ;-) The ? do appear to gathered in some areas and prevented me from finding the bombs, but i was able to slay the dragon.

Also add a mute button...

edit: more detailed description