It might be fine with you, but that way you will be infringing copyrights. And you don`t want that.Sorry storyline is pretty much already planned out. I don't want it to be a parody... a regular game is just fine.
If you want to make a Halo game that is not a parody, you will have to get an official, written permission from Halo developers, which I am almost completely sure you will not get as you are an indy developer with no background (no offence) and no company wants to risk their worldwide-known trademark that way.
You can have a "regular" storyline and all, just clearly state somewhere on the title screen that your game is in no way affiliated with MS/Bungie, they are official owners of all Halo trademarks and your game portrays series in a sarcastic way, as a parody.