Check out Apparatus' sequel, now free and open source - Principia

Level backgrounds

In Apparatus 1.0, 9 new backgrounds were added to the game in addition to the original default wooden background. These backgrounds can be selected from in the background picker in the sandbox.

The following backgrounds are available in the game (within parentheses are the names given to them by ROllerozxa in 1.2.2):

The two final backgrounds were added to the selection in the unofficial 1.2.2 update. The Christmas background already existed in the game since the 1.1 Christmas Update, but was not selectable in the background picker until 1.2.2. When active, buckets will turn red.