Challenge

Challenge is an extra game mode from Mega Man Powered Up, Mega Man 9 and Mega Man 10 with optional challenges that the player can try to achieve. Those vary by being small stages with their own challenge or an objective to be done in the main game mode.

Mega Man Powered Up
Mega Man: Powered Up has 100 challenges, being 10 for Mega Man (available from the beginning), 10 for each of the eight Robot Masters (the character must be unlocked to play his challenges), and 10 being boss battles (unlocked after completing the game. Except for Old Style, all character can be used). Although optional, completing all challenges will make Proto Man available as a playable character.

Mega Man 9
If certain challenges in the main game are accomplished, then players gain the following recognition for it.

Mega Man 10
Mega Man 10 has two types of challenges. The game also gives a rank for the challenge completion, starting with Rank E at 0%. Completing 25% of the challenges will increase the player's rank to D, Rank C with 50%, and so on until Rank S with 100% completion.

Challenge 1
A series of small stages with specific conditions to be completed. Challenges 38 to 88 are unlocked by meeting the specific sub-boss or boss (all varieties with The Keeper and Weapons Archive) in the specific difficult (Easy/Normal/Hard) in the main game. Challenge 1 is 98% of the total, challenges 1-25 being equal to 1.4 % from the total each, and each goal from challenges 26-88 are 0.5 % from the total.

Challenge 2
Challenges for the main game. Except for Superhero (Hard only) and Headbanging (Mega Man only), all challenges can be done with any character in any difficulty. Challenge 2 is made of 2% from the total.

Trivia

 * A glitch causes Time Man's attack to pass through walls when fired in a specific point between a wall and a spike, allowing players to complete his ninth challenge in less than four second.