TL;DR: Arcade, fast paced, quite difficult action/puzzle game with little stealth emphasis.

TL:
Gameplay: You probably won't get the stealth feeling you're looking for in this game, it's too fast paced and quite difficult, with emphasis on restarting levels until you get it right, rather than calculating a plan of action at first sight. You will repeat some levels so many times to unlock it fully, that it will become frustrating and stop being fun. After you restart a level a couple of times until you find the fastest course of action, you may become extremely volatile when you realise this game is not glitch/bug free and something won't just work on the 10th try (a switch may activate as you jump away from it, a robot may not move over a plain surface altough it should, etc.). Highscores are good and all but when each level is timed it will convey any other feeling but stealth.

Sound: The music is retro arcade style, which is not to say it's bad, it's just not something to keep you around for long. The sounds as well.

Visuals: The visuals are fine, it's like a pixelated film-grain, this won't bother you, and it's good for the type of game SBD actually is.

Story/Narrative/Context: Almost non-existing, and since it's displayed briefly on the walls as you pass by, you might miss a few while trying to move fast.

Conclusion: Don't get this game if you want a stealth game, but get it if you want a difficult platformer with fast paced action and some stealth nuances. The game is not bad, it's actually good for what it is, just don't be confused by the Stealth in the name since you'll regret paying for it. This ain't no Mark of the Ninja :P