Super Smash Bros. for 3DS is pretty fun. I can't play it for more than about an hour, 'cause I start getting headaches, but I've gotten pretty proficient at it. (Right now I can defeat Lv. 6 CPU players consistently in a 1-on-1 match.)
The biggest obstacle was the controls. I've only ever played Smash with a GameCube controller, which is super different than the 3DS. Giving the buttons different shapes makes a big difference in how your hand aligns to it.
I ended up reconfiguring the controls to:
I think this scheme works for me because I've been playing a lot of Super Mario World recently, and SMW uses B for jump ("A"), Y for dash ("B"), and A for spin jump ("X"). (It also matches the controls for Smash Bros. 64, which is where I got the idea for the scheme.)
Regarding characters: 48 characters is a lot. Right now, I've unlocked up to Ganondorf. My two mains right now are orange Kirby and red Lady Robin.
Kirby's always been my favorite Smash character, and I love that they added an orange skin for him. (Orange is [theoretically] my favorite color, and I always played yellow Kirby because he was closest to orange.)
I'm not sure why I originally started playing Robin, but I really like her moveset. It has a nice balance between ranged and melee moves (and I really like Arcfire). The "running out of mana" hasn't been a real problem for me, 'cause I try to avoid stale moves. But I still haven't quite figured out how to use her down-B or Final Smash.
I'm still not used to all the stages yet. The Omega Forms are a good idea, 'cause it lets you get some variety in scenery while still satisfying the competitive crowd. But I think turning them all into single platforms is super boring. Maybe there could also be a Sigma form, where the stage still has a unique layout, but none of the weird gimmicks.
I think the AI is always smarter than me...even on Level 6. Like, they're really good at shielding and noticing when I'm about to attack them, which are tactics I've never quite gotten the hang of.
The only real advantage I think I have over the AI is that they don't seem to expect you to throw item capsules at them to open them. And occasionally they just forget to notice Kirby winding up his hammer and standing right next to them.