I found it a little difficult to use, but was able after a lot of attempts to put some 'voxel' type blocks together. I too did an Isometric game. Your submission has an obvious Minecraft feel so I'm guessing that's the gameplay that should be attempted. I'll have to come back and give it another try, perhaps during the day and not at 3:40am when my brain doesn't want to work much more for the night.
By the way, my submission is also just HTML, and JavaScript - kudos to non-game engine games!