Challenge

Challenge is an extra game mode from Mega Man Powered Up, Mega Man 9, Mega Man 10, and Mega Man Legacy Collection 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.

Mega Man Legacy Collection
In Mega Man Legacy Collection, Challenge Mode allows the player to play different aspects from Mega Man through Mega Man 6. One aspect is traveling through parts of different stages where the player must reach the black hole that functions as a portal which will transport the player to a different stage area, while another part is facing bosses, both Robot Masters and the fortress bosses, most notably the Wily Machines. The bosses from Mega Man 2 will take the same amount of damage from MM2's Difficult Mode. The player must complete the challenge within the time limit that is listed and can earn normal, silver, or gold medals depending on how fast they completed the challenge.

Unless if restricted, Mega Man can use any of the Special Weapons and other special equipment from that respective game, with their weapon energy automatically re-filled when transporting between different challenge areas. However, the current energy in the life meter will not regenerate and any collected Energy Tanks will disappear unless if used before the player enters the portal. Mega Man can also have unlimited lives, however the time cannot be reset when he dies and he must always start over at the beginning of the current area within that challenge, therefore this gives the player less time to be able to complete the challenge within the time limit.

At the beginning only a few challenges will be available, but by completing the challenges more will become permanently available. It should be noted the game's special pausing (from opening their special menu) is the only way to pause the clock as opening the regular menu (or using MM1's pause glitch) will still run the clock.

Nintendo 3DS challenges
The Nintendo 3DS version can also have additional challenges submitted by fans that are obtained with both having the New Nintendo 3DS, and the Mega Man amiibo from Super Smash Bros. for Nintendo 3DS / Wii U. They were submitted by:
 * Amie Falamie
 * Brandon Valenzio
 * Jason Marciniak
 * Jerry Allshouse
 * Joseph Collins
 * Joshua East
 * Keelan Cliffon
 * Nathaniel Hoover (Fortress Fun House)
 * Nikias Källarsson
 * Tom Lyman

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.