Which anime are you currently watching?

[Cyberxion]

How is Captain N? I've never seen any of it, but the other Nintendo cartoons kind of scare me away from it.

It's probably going to be the same case with this one.

It's the story of a kid named Kevin Keene who, along with his dog Duke, gets sucked into the Video World one day while playing Nintendo in order to help save it from evil. There he joins up with a Princess who leads a team of freedom fighters consisting of Megaman, Kid Icarus (so-named, rather than by the name the game gave him, Pitt) and Simon Belmont.
Aside from Kid Icarus, who's only other off-character trait aside from his name is that he adds the suffix "-icus" to pretty much everything he says, the other two characters both look and act almost nothing like you'd expect them to.
Megaman is close, but he's green for some reason, and adds "mega" to all of his sentences, both in front and at the end of them, sometimes both in one sentence. He doesn't ever really shoot his mega-buster, nor do I recall him gaining the powers of defeated enemies.
Simon Belmont is dressed in a blue Bomber's jacket, wears flight goggles and has yellow hair. He's an incredibly vain lantern-jawed buffon, and is always tussling with Kevin for the attention of the Princess, usually screwing up in a colossal way. He still uses his whip, so at least that much is true to character.

The villains fare a bit better when it comes to resembling their videogame counterparts, save for their leader Mother Brain, who is a giant brain in a tank with an odd face on it that looks sort of like what you'd expect a cross-dresser to look like, and she talks like Little Richard. Dr. Wiley, King Hippo and the Eggplant Wizard round out the team of misfit villains, and as stated, do a good job of staying pretty faithful to the source material, at least when compared to nearly everything else in the show.

The story has the characters visiting various game worlds in order to either foil Mother Brain's plans, help a character or characters in need, or search for a way to bring Princess Lana's father to Video Land. That's pretty much the crux of the series, with the only variations being the settings that the characters visit, as well as the characters they meet there. It's pretty standard 80's fare though, so don't expect anything too compelling and you'll be satisfied.

The animation is pretty tight. Nothing amazing, but if you consider that it too is standard 80's animated fare, you might appreciate it a bit more than you otherwise would. However, if you're in it to see some of your favorite videogames faithfully recreated on the small-screen, you're in for some major disappointment.
On top of utilizing videogames that don't really warrant the animated treatment a bit too often, most of the worlds that you would want to see look nothing like you'd expect them to, and feature characters that look and act nothing like their videogame inspirations. The Zelda world for example, while being sorta cool for featuring character designs for Zelda and Link that are pretty close to the Mario Super Show designs, as well as the voice actors from that show, looks alot more...high-tech than you'd expect Hyrule to look.
None of that is overly off-putting, but it would've been nicer for them to have drawn inspiration directly from the games, or in cases in which it was available, the concept or game-manual art. It sorta stinks when you consider all the wonderful artwork in the Zelda manuals that painted a very different picture of Hyrule than that of the show, for example.

It's a decent package, but I think for me the decision to buy it was based more on nostalgia than anything. I think that if the other Nintendo cartoons from around that era put you off, this might not change your mind.

Also what's this Super Mario Bros 3 cartoon? I've not heard of it at all, is it any good?

I only caught a bit of this back when it first ran, and can only really remember that it was pretty-much a continuation of the original Super Mario Bros. cartoon, but was way more faithful to the source, and was all around more fun to watch. Not that the original SMB cartoon was terrible mind-you.

I'm going to see if I can't chase it down and check it out again.