Fun idea, however, it felt really really random. The special effects didn't change any of the regular tactics of RPS, except that you were kinda obligated to take the special effect because it was always better than regular play.
I think with two small changes the game would be much more enjoyable to me:
1) Have both players see the card the opponent has drawn. This way you can reason about what he is gonna do: "Oh it has a special effect on an attack win, should I play defense or will my opponent anticipate this and go for a regular win with support, anticipating my defense play?"
2) Have some cards with special effects provide an effect for every choice. This way you don't take the choice away from the player (Since right now taking the effect is always preferable over not taking the effect)