The movie ends on a heartwarming note, with Blue and Red reconciling their friendship, and Blue and Pink finally having an episode that doesn't culminate in a ruined date.
The series finale, Figured Out, is primarily this. Blue and Pink get married, as do Red and Stacy, although the latter pair eventually break up over arguments. Red reconciles with Stacy's sister Purple, who he's consistently derided over the entire series. With her self-esteem restored, Purple gradually turns into a normal stick figure as her relationship with Red develops. Stacy pursues a nursing job and helps deliver Pink and Purple's kids, and is visibly on good terms with Red despite their break-up. Red and Blue's daughters meet in kindergarten and look to have a promising friendship as their fathers did. The episode ends with Red and Blue meeting on the street by chance, catching up with each other before heading off to watch cartoons together. Considering how batshit insane the series is and how often Blue gets shafted, this sort of ending came as a very heartwarming surprise.