ShadowCaster looks very stylish, and is quite innovative in terms of gameplay and story. A shape-shifting protagonist, especially with such a wide array of forms he can take is anything but commonplace, and here it was implemented with much thought about balance and gameplay variety. There's also this "Raven look" of textures and monsters, also observable in
CyClones, another early project of the team, that would later become distinctive in
Heretic and
Hexen.
The engine is quite comparable to that of
Rise of the Triad, if not the same (both games run on a modified version of the Wolfenstein 3-D engine). It imposes some noticeable limitations on level design and layout, but the extensions like the player's ability to fly and swim underwater (apparently, using the same principle as in
Duke Nukem 3D, when diving actually teleports the player to a different location that simulates underwater environment because of the engine limitations that do not allow room-over-room level architecture) make up for it, and the resulting experience is quite diverse.
The mouse-and-keyboard controls aren't the most easy to use, but they aren't inconvenient, although probably not as well suited to real-time free movement RPGs as they are to the classical style computer RPG games.