Disney Sports Skateboarding serves no purpose in this world, save to exemplify and showcase everything that can feasibly go wrong with a skateboarding game.
Disney Sports Skateboarding is what it sounds like: a game featuring all your favorite Disney characters--including Mickey Mouse, Donald Duck, and Goofy--grinding it out on skateboards. Obviously the game is meant to cater to a younger audience, and as such, it tries to simplify the gameplay of many popular skateboarding titles. Instead, it somehow manages to do the exact opposite, making the game's control scheme and goal system needlessly complicated, and ultimately making the game nothing more than an unplayable mess.
The game's goal system is also quite bad. Each level has a set of goals that must be completed in order to advance and unlock new levels, skateboards, and outfits. Most of these are the run-of-the-mill goals found in essentially every skateboarding game available, such as scoring a certain number of points, knocking over random items, or reaching a series of checkpoints. Some of these can be achieved fairly easily, but many of them are insanely cumbersome, especially the checkpoint goals. Even on the first level, players must collect hundreds of checkpoint gems in a single run. Granted, many of these gems are set up in a row, allowing you to hit a bunch at a time, but trying to locate them all, as well as perform the timed jumps and grinds necessary to get to them all within the time allotted, is mind-bogglingly difficult.
On top of all of this are the game's poor physics. Grinding, for instance, involves absolutely no skill whatsoever. Simply executing a grind will allow you to grind on that object indefinitely, without any need to worry about balance or loss of speed. You can also begin grinding on object off a vert trick if there happens to be a bar or rail nearby, as your skater will just sort of immediately gravitate to that object as soon as you press the grind button, regardless of your positioning. Momentum is also not an issue in any way, as you can skate up hills or staircases without slowing down at all.
In summary, Disney Sports Skateboarding serves no purpose other than to exemplify and showcase everything that can feasibly go wrong with a skateboarding game. Even if you are a fan of skateboarding and Disney, do yourself a favor and forget that Disney Sports Skateboarding even exists.