I played the very first one back at university, on my room mate's N64 emulator on his computer. That felt easier to understand. I played a mean Samus back then.You've never played a smash bros game before? The basics are simple: it's sumo wrestling. You win by forcing your opponent out of the arena, and the more damage you apply to them (raising their damage meter, which is shown as a percentage) the further they fly when you hit them.
Now, though, it feels like there's so much more going on. Also, the 3DS screen is significantly smaller than the computer screen I used to play on, which makes it harder to see the details of what's going on.
Going to give the demo some more play time, see if it grows on me, but right now this is feeling more like a pass than a buy, for me.