Basically, when you hit enter to start the game, it asks you for a new level name. If you leave it blank, it will ask for a level to load. If you leave that blank, it will load the default level. Probably the best thing to do at this point would be to enter in a new level name, which will load the default level, but if you choose to save your level, it will save under the name you gave it, rather than overwriting the default level.
WASD moves the character. The 1 - 4 texture/type settings for objects can affect what happens to the character. For instance, that red ramp to the left of the character in the default level increases the character's speed and jump height. There are currently only two "boost" objects, so hitting 3 or 4 when those are selected will just turn it into a black box that does nothing. In the editor, there are two spring objects on the bottom. The second one is actually a "boost" object - still working on making something for the HUD there. Anything you click on will show in the top right of the screen, so the rest you can work out as you go.
Here is a random screenshot, because it feels weird putting a download link without at least showing you something.
Yup, now you know you want it, right?
http://www.sendspace.com/pro/dl/usx5zm
All feedback is totally welcome.
