MSH-RPG has simple game mechanics so that you'll focus on the story more so than the game mechanics...
For me, I do use an expanded version of MSH-RPG.
And I also use a lot of 'House-Rules' to help with Character Balance, so that one player isn't running a 'GOD' and another player gets stuck running a decrepit ho-bo bum.
Some 'House Rules' I use.
Character Points : Basically give each of your Players a 'Set Amount of Points' say 400 as an example. And each player can divvy up their 400 points anyway they want to the Character they are building for the Game Campaign.
Fighting = Crit Chance for both Melee and Ranged Attacks
Fighting = How many Multiple Actions you can make per game round ... EX:20 = 2 Actions / Round ... AM:50 = 5 Actions / Round
Agility = Distance moved per Game Round ... EX:20 = 2 Areas / Round ... AM:50 = 5 Areas / Round (End result is Running Speed)
Strength + Agility divided by 2 = Melee Hit Power
Strength = Blocking Constitution of 'Block Feat'
Endurance = Core Constitution for 'Survival' Feat Rolls
And a lot of others for the RIP Ranks for Casting Magic Spells or heavy damage blaster attacks.
For me, every Character has a 7 Category Format I use to Cover Game Mechanics and Character Building.
1. FASERIP / HP / KP
2. Defensive Powers (Avoidance Powers / Armor and Shields / Fast Recovery of HP or KP)
3. Offensive Powers (Single Target Blasts and Beams / Melee Attacks and Defense / Area of Effect Attacks)
4. Sensory Perception Boosters and Powers; and Mental Defensive Powers.
5. Self-Buff Powers that increase the Character's FASERIP / HP / KP Abilities
6. Travel Powers such as Flight / Super-Jumps / Teleportation / Super-Speed Running / Climbing / Swimming ... etc.
7. Talents / Skills / Personality / Social Networking / and some History as to How the Character got their Abilities.
But, put all of the Game Mechanics aside, try not to become a 'Rules Lawyer' and try to focus on a good story line...
For me, I find that most players enjoy Storyline problem solving, rather than just flat out Game Mechanics Combat.
As an Example: I ran a Game Campaign based upon Galactus and The Borg; where the Players had to infiltrate a massive Borg Space Ship in our Solar System. The Players had to face all of the various Borg sector bosses, defeat them; then confront the Head Honcho Borg Boss to get the Borg out of our Solar System.
Each Borg Sector Boss was completely unbeatable by Game Mechanics Combat... The Players had to solve situational problems to move forward in the Game.
One Boss you had to Free from Borg Slavery, Another you cause a Ship Riot to occupy the Borg Boss while you get away, Another Boss you basically avoid them as much as possible, Another Boss you had to Trap ... etc, etc...
Then after you defeat all of various Borg Bosses, the Players discover that millions upon millions of Borg had enslaved Galactus and were using his body as their space ship....
The end result is the Players had Freed Galactus from the Borg; and now Galactus is hungry for a Juicy little planet, like Earth.
My table of players 'LOVED' this Game Campaign because they could play their High-Tier 'GOD-LIKE' Characters...
Vegeta Voice: over 9000!!!!
But even still, the Borg Bosses were not a 'Push-Over' and they had to solve reasonable problems to move forward in the game... And at the end the Players were all like ....
''YEAH!!! WE JUST BEAT THE ENTIRE BORG FLEET!!!!! ....... AWWWW FUG!!!! WE JUST RELEASED GALACTUS, RITE NEAR EARTH''