MSH has a quick and easy character generation process. Characters are created by rolling for origin, ability scores, powers, talents and deciding on a name. It usually takes less than 10 minutes and offers an impressive variety in characters created.
The game has a light ruleset that encourages roleplaying. Most conflicts are resolved with a percentage roll and a consulting table with the GM having a lot of flexibility due to rules being mostly just guidelines.
Karam system is used for 2 things in the game - advancing the character (getting new powers, abilities and raising ability scores) and improving character's rolls. Since most players tend to focus on advancing the character, the secondary function of the karma system is often wasted potential.
M&M includes a variety of archetypes that players can base their characters off of. There are 15 archetypes to choose from. For example, there's a speedster archetype for Flash-like characters and shapeshifter archetype for Mystique-like characters, etc.
Characters are built by expending Character Points on abilities, skills and advantages, and by choosing powers and complications. To balance the characters, the game imposes certain restrictions on what's possible based on game's chosen power level.