I need 4 x 30-40 second animations for educational videos

Design details: Cartoony, educational, fun. Opening sequence per planet should have a satellite photo of the planet.
Target audience: 8-9 year olds
Ideas for the visual style: Cartoony, videogame, educational, fun
Things to avoid: Too realistic, corporate
Extra notes: We require 4 x animations all made to the same style, for children from ages 8-9 to view and learn. Each animation will then be followed by a quiz (we will develop the quiz). So the videos should be engaging, fun and clear when determining the facts, children should absorb the info easily.
There will be one animation for each of the following planets: Venus, Earth, Jupiter and Saturn.
These animations are part of a bespoke iPad app (about the Solar System) created for a PRIVATE event with around 150 children.

Storyboards, scripts and moodboard will be provided to candidates.

Will we need first visuals onone of the videos by the 4-5 December, and completion of works by the 16th of December.

We have a maximum budget of £500 in total to produce all 4 x videos.