Thanks! The score is just the amount of seconds it took you to complete a level, then I load the high scores in reverse order so that player's are ordered by how quickly they completed the level. Originally I wanted to score players based on how few minions they were able to complete a level with but like you said, spawning minions is half the fun so I made scoring time-based instead!
I noticed the camera is a bit frustrating too, seeing all minions is kind of important for level 5, but it doesn't help the other levels much at all.