I've played the original Pokemon Rumble for WiiWare and I thought it was an overlooked fun time of a game. Sure, the 6 levels are pretty much copypasta'd over and over, but the fun part is running around in a beat-em-up but with Pokemon, and getting progressively higher leveled pokes!
However, my favorite part of the game is getting up to three other people in on the fun at the same time, which is easier on the wii than on the 3DS, unless you know a bunch of other people with the same system and game. Having not played that specific version, I'd say consider picking it up if you can find a cheap used copy, but without being able to easily play with friends, I feel the game would lose a lot of its fun and addictive quality.