Ignoring unrated levels, this is Insendium's second ever demon level, which is insane if you consider how fun this is. For its time, it manages to introduce so many unique gimmicks into the gameplay: release portals in the wave, the famous cube-wave part, a mini wave click that fades to black right before you reach it, meaning you have to do the click blind, and of course, the awesome dual part at the end that actually uses the weird collision thing that dual ball has. Kudos to Insendium, really.