Need a Graphic Designer to reskin 2D game

Hello there, I bought an Unity game [login to view URL] and want to reskin it. The general idea is the game should be about trains, so instead of the ball , there is a train running from point A to point B. I attached sprites found in that asset to guide you. As a final result I want to have sprites reskined, ideally with the same filenames. Please provide me images how assembled game screens look like. Also please show your portfolio. Thank you!