No, there are just two. The first ending is shown when you finish the seventh level without all of the gems, or with all of the gems but without doing something else critical. To get the second ending:
Get all of the gems, restart level 7, and evert right at the start of level 7 (where your gem total is displayed). Finish this version of level 7, and you'll unlock level 8; beating it shows the second ending.