Personally I'd like it to be a rogue-like (probably more akin to Binding of Isaac than actual Rogue), they could keep the same basically game play and just crank it up to eleven with randomized power-ups and enemies...
I'm not really sure that would benefit
Mysterious Murasame Castle. Most of the original game is based on rogue memorisation and pattern recognition, so I guess the
Souls series is the closest modern equivalent to it.
But I dunno. Action games aren't as much of niche genre any more, especially 3D ones, but making a
Souls clone would also detract from the uniqueness of the IP. Not to mention
Souls is a very specific niche that is already filled, and most fans of that style of gameplay wouldn't play a game just because it's similar to it.
Since a lot of of the combat of
Murasame Castle focuses on dodging and timing, I could see it working in a 3D environment if it used a combat system akin to the (first two) modern
Ninja Gaiden games. Maybe it could be structured like
Ninja Gaiden Black, which actually had pretty open level design, albeit with a few more branching paths.
I think if they can prove their worth again, Team Ninja could be a good fit for
Murasame Castle. While they've had their blunders in recent years, the
Ninja Gaiden 3 remake for Wii U was a modest effort to make the game a little more tolerable, and while it still wasn't
good, at least they managed to make the core combat functional. They've still got some talent in there somewhere, they just need a better sense of direction. Team Ninja also has a very Japanese sense of style, that could fit well and enhance the series. Koei Tecmo seems to be the only developer actively supporting Wii U at the moment, and if we want a glorious HD revival for
Murasame Castle, it would be logical to give the rights to them.
whoa that was a tangent