Sonic Powered announced the digital version release of the Tetsudou Nippon! Rosen Tabi: Ooumi Tetsudou Hen train simulator game which released in 2015 May in Japan in package version. The game going to costs 6264 Yen (with tax) but until September 28, 2016 you can buy it for 3980 Yen (with tax).
If you like the series but you are waiting for the digital version or with a special price now you can grab it!