From the screens you can see that the game will have gameplay very similar to earlier games in the series, with all of the unique gameplay elements we've come to know and love such as the skateboard and the gradually decreasing stamina bar.
Totally new however are minigames - It seems there will be a number of them included in the game which give a unique twist on the gameplay, such as collecting as much fruit as you can within a certain time limit or riding through a completely 3D level on the skateboard! There will also be online rankings, presumably for both the minigames and your single player scores. You can also test your button mashing speed to try and beat Takahashi Meijin's (The man who Master Higgins is based on, as you might know) record of 16 presses per second, which earned him the nickname 16shot back in the day.
Adventure Island: The Beginning is perhaps the most surprising Hudson WiiWare game yet - The last main game in the series was Super Adventure Island II on the SNES way back in 1994, and since then there's only been a few Japan-exclusive mobile phone games! There was an Adventure Island game on the GameCube as well, but this was simply a remake of the original with updated graphics and music.
As such we quite look forward to this release - Judging by the title it will be a prequel, so it should contain only the main elements that made the other games fun without any unnecessary extra stuff (Aside from the minigames!).