>>> Combat is not very well balanced. You can only kill skeletons with fireball, staff does too little damage.
Your main dps skill is Fire Shield, where, you can still melee or cast fireball, while being immune for 3 seconds, and it does significant damage to an enemy in melee range. Enemies are quite easy to kill if Firesheild is used.
>>> I played the game, died 2 times then quit.
Did you purchase health potions and use them when needed? They help a lot.
>>> When i hit escape, i can't switch to fullscreen again.
You can click on the Fullscreen button on the main menu to go back to fullscreen. As you know since it is a HTML based game, escape will take the browser out of fullscreen mode.
>>> there aren't too many markers which could help with the spatial awareness imo.
You can interact with the torches (like turning them off) to set a bread crumb, so it will be easy to know which areas you have explored.