Our game was co-written. Please do NOT fail to include other authors in your submission if they want credit. Yes, you can split the profits and everyone who contributed MUST sign the contract, but it is up to the authors how they want to divide credit. This is something that any authors who are partnering together should be able to discuss and agree upon even before the game is ready to submit.
I have described this process before, so you may find this thread helpful:
And be careful about looking for other writers and coders. While it is possible to find people to work with creatively on the forums, there are also rules about how you can solicit those services here.