I really enjoyed it, great first game on your part! A few things to consider if you re-release this or have a future project
-When I press down the screen scrolls down. the down arrow isn't used, but it caused me to die a few times due to mis-pressing it.
-When I click off the screen, I cant click back into the game, so the arrow keys don't do anything until I refresh the page.
-This sorta feels like a techdemo rather then a game. Try fleshing it out. Now that you've got the basic platforming mechanics down, maybe you could try implementing something that makes yours unique!
Good luck!