The 3D animation was less... annoying than I thought.

This is kind of a retcon/reboot, including the origin of Snoopy's fixation on the Red Baron, and Charlie Brown's love for the Little Red Haired Girl.

Nits follow.

The plane runs for a full year without any refueling? Yeah, right.

In the winter, the kite-eating tree is shown to be right next to the (frozen) pond. However, at the end, the kite-eating tree is near a fence, nowhere near a pond.

Also, since the LRHG was out of town when the book report was assigned, and was going to be out of town until the day the report was due, why did Miss Othmar put her name in the jar?

Linus is Lucy's little brother, not her twin brother. Why is he in the same class as Lucy? [Potential anti-nit, it's a combined grade class].

Why are no teachers/administrators involved with the assembly to honor Charlie Brown? This is a recurring nit in ALL Peanuts, both strips and animated.

How did Snoopy get into and out of Franklin's bathtub?

NANJAO. The scene where Snoopy appears in Woodstock's nest to tell him to hush was very Monty Python-esque.

In the winter, the kite-eating tree is shown to be right next to the (frozen) pond. However, at the end, the kite-eating tree is near a fence, nowhere near a pond.

Come on, the kite eating tree is obviously capable of moving around while stalking its prey.

Linus could have also skipped a grade.