The powers I designed so far come in three easy levels: Low, Paranormal and Superhuman. I need to set some costs for what we laughingly call play balance (Like Superman's drawbacks pay for all his powers. He can destroy the planet by blinking rapidly and has the most rare and exotic weaknesses available.)
Every Superhuman level power costs one level of experience. A character can start with negative levels but after play begins he will not progress in levels until he buys off the negative levels.
A Superhuman power can be traded for a Paranormal, and Low level or three Low Level powers. If the player wants to have a character with only one Paranormal level power or two Low level powers the character can give up one roll to increase an attribute for each Low level or two rolls per Paranormal power.
A character can purchase an improved weapon built by a Superhuman genius working in the rear areas or home country. Picking two of the paranormal intelligence mods for a weapon costs an experience level.
(Reprinted here for your convenience or check the link here.)
1) increasing damage die to the next size die
2) increasing usage die to the next size die
3) give a -2 bonus to rolls or +2 penalty to opponents' rolls
4) miscellaneous (for example, the device is miniaturized or concealable).
They also trade in their rifle for the device. A character taking a melee weapon is also provided with a pistol.
To keep the ordinary heroes of the greatest generation from being overshadowed 'normal' but exceptional soldiers could receive some bonuses as well (no powers but they train harder). Super powered people being led by a normal human is a staple of comic books. They could receive extra experience levels at the start (though they have to buy them off the same as the levels used to pay for powers.)