Platformer Tutorial Very Useful
I found out that in one of the playable screens you can walk off the screen and come back on a lower "level" than the previous; so I can go low enough to get past the door without opening it and jump back onto the original "level" :P. It's the one where the door is introduced. Other than that though, this tutorial I find more useful than another one I used on another website, since it didn't include opening doors and enemy attacks.
