Umihara Kawase Portable
What should have been a dream return for Umihara Kawase after eight years turned into a nightmare. Umihara Kawase Portable was developed without the involvement of original series programmer Kiyoshi Sakai, and Rocket Studio, the development team responsible for this version of Umihara Kawase Shun didn't get the physics working properly, among other bugs affecting the game's playability.
In addition, the visual perspective is slightly altered compared to previous versions of Umihara Kawase Shun, in a way which better shows off the 3D platforms; however, this can sometimes make it harder to target platforms with the fishing line.
The two small advantages Umihara Kawase Portable has over other versions of Umihara Kawase Shun are the placement of the score/time/lives information - much closer to the top and bottom of the screen than in other versions of Umihara Kawase Shun; and of course with the widescreen of the PSP, you can see a bit more of your immediate surroundings. Such advantages don't matter much, though, when compared to the much more important disadvantages this version has.
Umihara Kawase Portable would have been the first Umihara Kawase game to be released outside of Japan, as Natsume had plans to publish it in North America with the name Yumi's Odd Odyssey. However, this release was eventually cancelled, and Natsume would reuse the Yumi's Odd Odyssey name a few years later when they published the North American release of Sayonara Umihara Kawase.
Ultimately, players looking to get their portable Umihara Kawase Shun fix should look elsewhere. If playing on PSP is the only option for you and you have a Japanese PlayStation Network account, you can buy and download the PlayStation version of Umihara Kawase Shun ~Second Edition~, with the added bonus of being able to play it on a PS Vita or PS3, should you have one of those. Otherwise, if you have a Nintendo DS, you can't go wrong with Umihara Kawase Shun ~Second Edition~ Kanzenban.