You should never attempt a level without taking a buddy with you, buddies are little mascots you can recruit that fly beside you during a run and provide additional support. There are multiple types of buddies on offer and each has its own useful ability which you can take advantage of to help you complete the mission. RC Tornado for instance recovers your rings when damaged and Dark Chao is able to boost your score for destroying enemies.
Buddies become unlocked by earning rings so early in the game you will not have many buddies to choose from and those that are available will only affect item usage. As you progress through the game collecting rings you will eventually have the required amount to unlock more useful buddies.
Chip
Effect: Chance of continuing after being defeated once per run: 100%.
Unlock: Buy for 2,500 Rings.
Dark Chao
Effect: Chance of defeating a missed enemy on the screen: 25%.
Deflects Eggman's Yellow Balls.
Unlock: Buy for 2,500 Rings.
Dark Chaos
Effect: Chance of defeating an enemy or destroying an obstacle instead of
getting damage: 50%.
Deflects Eggman's Yellow Balls.
Unlock: Buy for 1,500 Rings.
Hero Chaos
Effect: Chance of keeping all the Rings when damaged: 50%.
Unlock: Buy for 1,500 Rings.
Knuckles Omochao
Effect: Increases booster item duration for Power-type characters by 5 seconds.
Unlock: Chapter 3
RC Tornado
Effect: After the player's character is defeated, their buddy flies ahead collecting
Rings for the next 10 seconds.
Does not work in boss levels.
Unlock: Buy for 2,500 Rings.
RC UFO
Effect: Chance of collecting missed Rings: 25%.
Unlock: Buy for 2,500 Rings.
Sonic Omochao
Effect: Increases booster item duration for Speed-type characters by 5 seconds.
Unlock: Get to level 4 of Green Hill.
Tails Omochao
Effect: Increases booster item duration for Fly-type characters by 5 seconds.
Unlock: Chapter 2
Wizard Chao
Effect: Chance of producing the Magnet effect when using a Cannon or a Jump Panel: 35%.
Unlock: Buy for 1,500 Rings.
Yacker
Effect: Increases the area of effect of the Magnet by 50%.
Compatible with RC Tornado and RC UFO.
Unlock: Buy for 2,500 Rings.