More than simply based on the Disney Channel Original movie, the Phineas and Ferb: Across the 2nd Dimension video game could be considered an interactive part of the film. Those familiar with the movie will recall the "Brand New Reality" montage sequence where Phineas, Ferb, Candace, Agent P and Dr. Doofenshmirtz are jumping into one bizarre dimension after another while being pursued by evil Normbots. The video game's storyline fills in some gaps as to what exactly took place during this frantic dimension-hopping. The various dimensions our heroes pass through contain a number of references to certain episodes of the TV show that were not referenced in the movie. Two players can co-op play at the same time, or a single player can work with a computer-controlled partner.

The game plays like a typical platformer with numerous puzzles, mini-games and boss battles in-between exploring and fighting basic enemies. There are countless items to collect and special characters (each with their own unique ability) to unlock as well as costumes/skins that can be obtained for all of the playable characters. Once more than the two main characters are unlocked, players can switch characters between levels if they so choose. Weapons can be customized with different colors and sound effects once these are earned/unlocked. Additionally, there are many achievements/trophies to be won and an increased difficulty mode becomes available after achieving the final trophy. Background props change depending on what time of the year the game is played (e.g. jack-o-lanterns are visible around Halloween, snowmen and Christmas lights appear in December, etc).

This game should not be confused with the DS game that has the same title, but is otherwise a completely different game with an alternate plot line, other types of weapons, dimension levels and boss battles unrelated to the Wii and PS3 versions.