Good concept so far. I would agree; the map needs some work. I would start with an ajax call instead of a page refresh; I see you did this enhanced. Next I would optimize that to only load in the items on the map that changed, this way you are not reloading the whole map each time. This will make it faster and lighter on bandwidth. If you have any questions on how to do this, feel free to ask me any questions. I just released a real time massive multiplayer browser based game engine so I can provide advice if needed on the ajax stuff.
Something else that might be nice is making the tutorial move as the users moves through the game instead of them having to hit next. So once they complete one it shows complete.
Best of luck with the game.