I will just chime in to say that I never played Royal Rumble for years because I am not a wrestling fan at all and the theme just kept me from even walking up to it. I know that doesn't make a lot of sense since I don't have a fondness for Volcanos, and I am not too familiar with fictional space figures but I enjoy playing Volcano and Embryon.
But anyways, I did finally play Royal Rumble and I really enjoy that game a lot. Center ramp is way too easy and the left ramp isn't very hard either, but there is a lot going on with that playfield and there are some tricky shots to be made. As much as I love to play it I don't think I would put in my collection due to the theme but I sure do play it every chance I get.
I have played GNR a fair share as well and its not a bad game and I am not really impressed by that theme either but I have a lot more fun playing Royal Rumble.