Played the demo--- have to ask...
How much of this did you code yourself? It plays almost as if you pieced together zelda example after zelda example to make it do what it does... At times theres things that feel as if they would have been programmed by someone experienced, while other spots in the demo feel as if someone who's never used GM before programmed it :s... Things such as the camera scrolling, the collision issues, the millisecond delay in the rolling, etc feel very amateur, however you have things such as a typewriter text engine, beating heart engine, etc that would have taken more skill to create.
It's almost as if someone took a beautifully detailed painting and opened it up in MSpaint to fill in the gaps :x
Otherwise, if this is one of your first GM games, all I can say is keep at it - if you know how to implement so many prebuilt engines without error already then you're on the right tack.