All right, the last time I saw a 2D Minecraft created with GameMaker was in 2014. I've taken a look at your version and I think you're on the right track.
It would be great if you could implement hotkeys and improve the inventory system to make it more dynamic. From what I've seen, the world generation still lacks consistent mineral generation. Also, the lighting of visible blocks needs a couple of tweaks: if you go to the bottom of the map and dig a hole big enough, you'll get decent lighting even underground.
Oh, and wood is so scarce that it's worth more than diamonds!