The objects above the buttons are to choose whether you want to tile walls, spikes or blank spaces.
Test Level takes you to Test mode (it tests the actual level, not the level code)
The level code box is where you can get or paste level codes to/from.
The refresh button orientates all spikes and floor tiles (This is done automatically when the level is tested).
The get code button returns a code in the level code text field for the level you've just made.
The make level button creates the level from the code in the text field in edit mode (can be tested as well).
Erase level sets everything back to the base level (which is a large box).
World style toggles the world everything's set in (Cat Rescue's tiles don't show up for some reason, they default to Practice Mode, I'm looking for a fix)