Hold down Shift and click on the green flag for Turbo Mode. Change 'foldings'! For each value of 'foldings', the angle starts at 180 degrees and decreases to 90 degrees.
There's a nice Numberphile video about dragon curves: http://www.youtube.com/watch?v=wCyC-K_PnRY How to fold a dragon curve using paper http://www.cutoutfoldup.com/216-dragon-curve.php
