Sega is using the news section of one of its PC games on Steam to tease a new game. The company is known for using this method to drop hints about upcoming releases. The newest one has a picture of a sheep on the Bayonetta page, with "Baa" set as the announcement’s title. (Thanks, Wario64!)
As Wario64 pointed out, this could be a Catherine tease. That is the Atlus puzzle game with visual novel elements. The original appeared on the PlayStation 3 and Xbox 360 in 2011, and a PlayStation 4 and PlayStation Vita remaster with new content is coming out worldwide in 2019.
A reveal should come soon. Back when Sega used the Bayonetta page to tease Vanquish, the PC version released about a month later. After Bayonetta, Binary Domain, and Vanquish were teasing Puyo Puyo Tetris, we ended up seeing it appear later that same month.
The updated version of Catherine will come to the PlayStation 4 and PlayStation Vita in Japan on February 14, 2019. It will release worldwide in 2019.