Need for Speed: Porsche Unleashed is a racing game developed for the Game Boy Advance system in 2004, belonging in the Need for Speed franchise. It is a handheld port of the original copies released for the PlayStation and PC back in 2000 Need for Speed: Porsche Unleashed, but comes with very different gameplay mechanics.
Although it was the third Need for Speed video game to be released for a Nintendo console and the second GBA title after Need for Speed: Underground, the Porsche iteration was supposedly worked on earlier than the latter. 
As the name implies, this racing game is fully concentrated upon Porsche sports vehicles, and includes a full evolution of the brand's models from 1955 to 2000.
The game is based upon the series' traditional racing gameplay, with the player being given a default view from within the cockpit of the car - there is an option to switch to third-person view, as well. The game features up to 25 unlockable cars, all of which are different makes of Porsche, and has a range of different track courses appropriately situated in the European continent (as Porsche is a German car manufacturer).
The game also makes use of GBA's link cable system, supporting up to 4 players in multiplayer sessions.
The handheld port of Need for Speed: Porsche Unleashed received mixed reviews from the critics with a score of 62% on Metacritic, which was lower than the originals that it was under the shadow of.
The game was commended for its solid game engine and display of 3D graphics on the handheld console, with IGN stating that "the programming team's extremely impressive (at least for GBA standards) 3D engine that allows for fully texture-mapped 3D environments running at a relatively smooth framerate." 
However, much of the other aspects were criticised. IGN hit out at its "sloppily contrived single player competition structure", whilst the lack of "performance indications for any of the cars" was also frowned upon. They concluded that the "track design needs some serious tweaking" due to sharp 90° turns that the CPUs would collide onto.
In the end, the game received divisive opinions from the critics. On one hand it was dubbed "Porsche Unfinished" in a mockery of its name by IGN, whereas on the other hand Nintendo Power concluded it was "a fast and fun arcade-style racer with a strong graphics-display engine and minimal clipping."