• There's two jump buttons, and a hold button.
• The hold button, B, can be used to dangle from hooks, vines and red floors. It can also be used to drag red boxes.
• The two jump buttons, Y and A, jump left and right respectively. It's easy once you try. If you really dislike it, you can switch to single button jump on the main menu, but I wouldn't recommend it! Some things happen too quickly to stop and turn around!

• Level packs can contain many many levels, but each level must be played in the order layed out in the pack.
• No saves! If you die 3 times, you're right back at the start.

• Tap the middle icon on the titlescreen to enter the editor.
• Draw a level.
• Hold a trigger, and a Wipe/Quit and Test button appear at the bottom. If you test a level, and subsequently complete it, and you can then also Save it from this same Trigger-based menu. Note : You can only save a level if you've managed to complete it! You don't need all the gems, but you do need to get to the exit.

• The level will be added as a simple line of ascii text, to the bottom of the JNKPlat/MyLevs.lev file on your card (assuming you're using the DLDI version, and have added the JNKPlat folder to the root.)
• Each line is it's own level. Feel free to copy+paste these lines to build up your own little level packs.

Via PAlib forums