It's very unlikely the Rockman Unity app will come stateside in any official capacity, but that shouldn't stop you from enjoying it. Thanks to the gracious efforts of Replioid_21XX, you can download the .apk file right here. Don't worry; the app itself is free. This way you can skip the hassle of setting up a Japanese Google Play account.
Also, here's that fantastic wallpaper by Shinkiro in three sizes: 640x960, 750x1334, and 1080x1920. Normally this wallpaper is won by "defeating" Cut Man in-app. But hey, here it is.
Thanks again, Reploid_21XX! Enjoy, guys.