Welcome to my guide for Game Boy Gallery! This game's a lovely little gem. It contains five mini-games all with very simple but quite clever mechanics. It's quite likely you'll find yourself addicted, trying to beat your highest score of 715 points, wasting hours in the process.
Although possibly not as good Game Boy Gallery 2 (which includes four classic mini-games, but includes both the original and a reinvention of the mini-game with more complex mechanics added in for even more fun), but it really brings something worthy to the table. It's a game that you can pick up and play for five minutes for many hours. All of the games are not only simple, but very challenging.
Game A of each mini-game is basically 'Easy Mode'. As you collect points (the method to collect them differing in each game), the difficulty picks up. It keeps picking up until you reach the next century (100, 200 etc.) at which point it drops back. Reaching the next century is much harder than the last though, with the difficulty increasing each time. Game B is basically a 'Hard Mode'. You start with a much higher difficulty level and it only gets more intense as you go on.
The aim of each game is to score as many points as possible. You do this in a variety of ways, each depending on what game you're playing. You lose when you make three mistakes in any game (except for Ball, where it is Game Over after the first mistake). Mistakes are different, but generally pretty obvious in all of the five games. When you make one, you're notified, there is a pause, then gameplay continues. When you make three, it's game over and you have to start over from the beginning, or go on to a different game if you prefer.
That's a basic overview of the game. Now go and enjoy it!