Below the description there's a big "Download Now" button. When you click that, a window will pop up where you can (if you so choose) toss us a small donation. Donations are 100% optional, and you can download the game for free by clicking the circled text here:
That will take you to the download page itself, from there click the red download button next to "Ashi Wash 0.5 Windows (LATEST)" if you want to play the most recent build that we uploaded back in August of 2016, or the button next to "Ashi Wash Prototype Windows (OLD)" if you want to play the older, uglier version that Markiplier played.