Need Help with Game For Website

Hi all

I am currently working on a website.My website is a site that will show users where to play free games online and win cash or prizes..Where I need help is in making my own game whether it be slot machine..keno..poker..something to keep visitors coming back. (problem being I dont know how to do this)
I want the game to be able to keep them coming back while at the same time be able to register a high score for a chance to win prizes.
I currently do not have lots of funds to pay for this but would be willing to give a percentage in the future of profits made. Or an arrangement we can make.. ( I can't gurantee huge profits but I do have alot of followers as I have been winning alot lately and am asked daily where did you play at so I know this is of interest)
If this sounds like something you know how to do or are interested in doing feel free to email me at URL
Subject line I want to help
please include your suggestions and we can go from there thanks all for reading.