Dear Sir,
Thank you for giving me the opportunity to bid and if you want to work for you.
I have a lot of experience in video game creation and I could create the game based on Flappy Bird that you want. I would create it in Unreal Engine because in this way it could be multiplatform (Android, IOS, PC, PlayStation, XBox, Switch, etc).
If you want more information about me, please visit my profile or contact me.
Thank you very much and best regards.