As the title says, these are 3D slot games. They can be 3 Reel, 5 Reel and any other type of game that the normal 2D slot games can offer. The gameplay and the rules are the same; in fact nothing is different except the improved visual appearance.
3D offers greater opportunities for visual effects and better interaction with the player. The introduction of the games usually involves some kind of short animated movie to introduce the game to the player. You get the impression as if you are really entering in the casino, very nice touch for people who prefer aesthetics on the next level.
Slots with 3D video first appeared in 2011. Once they were offered to the players they attracted a huge fan base. People loved the themes and the intros that almost every different casino offered. They really stood out from the common slot games. In 2012 the demand started to go down, however even to this day there are players who still find these 3D slots very entertaining.
All well-known creators of casino games tried to experiment with introducing their own unique 3D slot games. Some of them are BetSoft, Sheriff Gaming, Micro Gaming and Net Entertainment. The most successful games can be found under the 3D Slot category and from there you can pick the type of game you want to play, be that 5 Reel, 3 Reel or even progressive slots.
To this day we have no information that there is a casino with slots that offers this type of feature. It sounds good seeing everything in actual 3D, but it is highly unlikely that somebody would want to play the game for longer time just because you get to play the game with cool 3D glasses.
Bottom line is somebody will create this type of game and we can only guess if the project will succeed or fail.