SNK Playmore has made every effort at the time of making a new KOF sprites drawn with HD. In the 1990s, its heyday, used to announce a new game they were working on, some time after marketing a arcade. Years later the situation has changed, and is no longer the same company before ... Unlike Capcom, which has already developed several games, most of them fighting Vs after KOF XIII, the company has kept a long silence, still recovering from KOF XII, a commercial failure.
When were developing KOF XII, once commented that, if the game sold well in the market, would start working on a new Metal Slug HD. Time has passed, and not only have not said anything more about it, but have not yet announced a new project they are working ...
The web Speksnk, explains the situation a bit: http://www.speksnk.org/foro/viewtopic.php?f=6&t=74766
1up, talks about a new Metal Slug 2.5D, http://www.1up.com/do/blogEntry?bId=9093851. A shoock Troopers 3, run and gun, this time, vertical, as Capcom Merc, 2.5D, could also look good, with a semi photo realistic, as Gouls'n Ultimate Ghost , Raiden IV, Sonic 4: Episode 2, or Sine Mora. Like Revolution Against Evolution.
Or finished with cel shading, as Viewtiful Joe, R-Type Dimensions, or Marvel Vs Capcom 3 FotTW.
True, the flat drawn 2D sprites or bitmaps especially in HD, is far more advanced than the polygonal graphics. But good results also with polygonal graphics, gaming and vertical side-scrolling 2D. And since they cost so much making new sprites or bitmpas HD, could work a good 3D graphics engine, and make good games with photorealistic semi finished and finished drawing comic cel shading. The cel shading technique, is that for me, has less travel, and the joint best sprites or bitmaps drawn the plane, with polygonal graphics.