Tamagotchi Version 4 Features:

(source: the entertainer)

• Skill Point System: This new point system enhances the Tamagotchi's life experiences by getting a career, going to school, or partnering!
• Increased Gotchi Point System: Players are awarded points at each stage of growth, and players earn points for playing games. Players can use points to purchase gifts for friends.
• New Games: Three NEW games are included to play! There are now 20 games in all!
• Single Player or Double Player Modes!
• New Characters!
• More Online Play: T4 Tamagotchi have online compatibility on their web site!
• Compatibility: Tamagotchi Version 4 is compatible with Versions 1, 2, and 3, so you can still talk to all your friends who have the older releases!
• Increased Friends Lists: Now hold 45 friends!