Altered Beast did exactly what it needed to do and nothing more. Sadly, this would be a common occurrence with Sega home ports of popular arcade games. They didn't add anything to entice fans to drop $40 to $60 all at once over paying a quarter or two for entry.

That always bothered me. I was like, surely they could have added an extra level or two, new characters, balanced the game a little better, etc.

Namco was great at this, especially when the Sony PlayStation came around. They added all kinds of home exclusive options to their arcade ports. Sega did a few small things with Virtua Fighter when it came home to the Saturn but it was nowhere near what Namco was doing.

Capcom is another one guilty of lacking arcade ports to the home. They pretty much did straight ports as well.