Developer Runes:
Free all the Mul-muls from their cages to unlock special Runes in each level. Note: Look in the “Extras” menu to see how many Mul-Muls have been freed.
Developer upgrades:
Collect all special skill upgrades to help your Heroes. To find them, look for the sparkling light. Note: Look in the “Extras” menu to see how many skills you have unlocked.