Alright... here goes nothing...

This game is an FPS, but instead of guns, you have your trusty arm cannon. This gameplay would combine both sword and gun gameplay together. Left click is to shoot and the right click is to use your sword. I figured, since melee combat would be the most integral part of gameplay, I relegated the melee button to right click in order to make this gameplay less cumbersome and as lightning quick as possible.

The sword animations gotta be lightning quick, but not too fast for the game to be too easy. 

And, as you fire your gun, you heat it up. Once your heat meter gets to a certain position, IE, more than halfway, you enter the "danger zone" which your sword gets twice as strong. 

Basically, your sword gets more red as your gun heats up

Since his arm cannon has no ammo, a heat meter is used to balance the gameplay to not have the player shoot all the time. When you overheat, you are unable to fire for a period of time. However, if you are overheating, your sword actually gets 4 times powerful, making you instantly kill enemies in one hit.

There's going to be more in store though. This is just the main mechanic for my game in terms of combat.