I replayed it today, and Level 3 is hard as hell, but I persevered and beat it! (Most of my issues were with the second and third rooms - the collision detection seemed a little unforgiving and the character tends to "skid" ... right into the obstacles) *Loved* the new boss fight, though. I was hoping there'd be another one behind the Big Door, but alas, it was just the ending.
(Once again, I streamed it, and I'll give you the timestamp tomorrow after I edit the video) :D