Cutesy Anime Hack&Slash for my niece?

Your request has been heard, and I am here to deliver the call.

Phantom Breaker: Battle Grounds - https://store.steampowered.com/app/329490/Phantom_Breaker_Battle_Grounds/

It's cute, it's cheap, and it's a very good game. It has multiplayer in it though and single player. I don't know if you can talk to other players online or not.

I honestly wouldn't limit your niece to anime ;)

Gurumin might be a good choice, I'd also recommend a few games:
Practically any of the newer LEGO games - the Marvel superheroes one is pretty good, and the LEGO Movie game is fun.
Speaking of Neptunia - I played Mugen Souls - it's a similar sort of game, may or may not be interested in that.
Perhaps Unbox - I found this really enjoyable.

Thanks again for all the replies so far, some really helpful info from you lot!
Could´nt have found all that stuff by myself :-)

I forgot one.

Dust an Elysian Tail. It's not anime, but it is an anime-style Metroidvania. (Has hack and slash elements) I think your niece might enjoy it. Story is excellent and the characters are mega cute. It's really cheap atm too.

https://store.steampowered.com/app/236090/

srsly could´nt find great britain, so Isle of Man has to do lol

I think it's listed under "United Kingdom." :)

Everything I could think of has already been suggested ^^
But although it's not a Hack & Slash, I would like to add
https://store.steampowered.com/app/253230/A_Hat_in_Time/
and
https://store.steampowered.com/app/360830/YookaLaylee/
Both are really cute and might entertain your niece :D

Also, Cyberdimension Neptunia 4 Goddesses Online is NOT and online game :3 You could kind of play with others, but it's just a an endgame feature and nothing you have to doo. The rest is just a cute Neptunia game where the characters play and MMO.

Happy early Cake Day :D

They might not fall directly into the "hack and slash category" (Cause they are rpg games at core)

But Ni no Kuni 2: Revenant Kingdom and Tales of Vesperia Definitive Edition suits the "cutesy anime" part perfectly.

https://store.steampowered.com/app/589360/Ni_no_Kuni_II_Revenant_Kingdom/

https://store.steampowered.com/app/738540/Tales_of_Vesperia_Definitive_Edition/

Let's see... some of these have already been mentioned but I guess I'll just add my two cents to it. :P

Recettear: An Item Shop's Tale (also the rest of the Carpe Fulgur Collection likely also count) - Just... if you wanna find the cutesiest game then this is a top contender. Light-hearted humor, bright setting and very likeable characters with silly quirks. The main character Recette is like a black hole that eats all your depression and lets only cheerfulness escape. The game does have a poorly (that is- not at all) explained friendship mechanic that could make progressing harder later on, but even if you lose (miss the payment) the game just goes "That's a downer. Luckily it was all just a dream! Now start over shortly after the beginning with all the shit you already collected intact. :D ". [joke]Also might teach your niece a thing or two about capitalism.[/sorta joke]

Giana Sisters: Twisted Dreams - Ok, yeah, it's a platformer, not a hack and slash. It's also bright and colorful and kids need platformers in their gaming lives. Also if my 10 year old nephew, who insists on using only two fingers on the arrow keys instead of three no matter how much I suggest it, can beat it, then so can your niece. (Ok, that's not completely true- the final boss kicked his ass, but that's the point where you swoop in and show how much of an amazing uncle you are by beating the big bad boss. :P )

CrossCode - Ok... yeah, maybe this one would be a bit on the hard side for a 11-year old. It's an Action RPG with a lot of puzzles. But, well, the gameplay is great, the story is nice, the characters are very likeable and she might learn something from the puzzles... I hope...

RWBY: Grimm Eclipse - Not sure how interested someone who hasn't watched RWBY would be in this one, but it is a rather simple Hack-And-Slash. As your character levels up you quickly start becoming rather overpowered and crushing everything, particularly when playing solo where the enemies are severely weakened and in lesser numbers. It has online co-op but she can safely play the game completely solo. (Allegedly there's also a mod for local co-op if you wanna play it with her. ;D )

Rabi-Ribi - Now I'm really pushing it... It's a metroidvania platformer with big bullet-hell-like boss battles (the bosses attack with bullet-hell-style patterns but you still have a health bar so no one-hit death). However, on the lowest difficulty (aptly named "Casual") you can tank so much damage that even a kid should be able to play it (and even if she still gets beaten the game offers to further make it easier after you die a couple of times). Anyway, if you can overlook the whole "Bullet Hell" part of the equation it's a very cute fun game. ^_^'

A Hat in Time - It's a 3D platformer... a very easy 3D platformer (As long as she doesn't play the hyper difficult DLC... just don't mention it exists.) It's cute, it's cheerful, it's fun and it has a little girl whacking stuff with an umbrella. What more can you want? :D

Phantom Breaker: Battle Grounds - A pretty straightforward beat-em-up (thing Streets of Rage but anime style). Has (optional) Split Screen co-op. :)

Shantae and the Pirate's Curse - Metroidvania platformer. Not sure where I'd put it on the difficulty curve. (I may or may not be kinda bad at judging games in that regard if the reactions of other people towards games I consider "easy" are to be taken into account.) Anyway, the game is a very good and generally a safe pick.

Fairy Bloom Freesia - Bet you never heard of this one before this thread. It's about a cute (and ridiculously overpowered) fairy protecting the forest by beating the shit out of some monsters in pure Hack-And-Slash. That's about it, really. XD

I think that's about all I've got. The only other games I'd recommend are the main Hyperdimension Neptunia games (particularly Re;Birth1 and 3, the other two get kinda really dark) although they might have a bit too much ""adult"" humor in them (nothing extreme, but stuff that a kid wouldn't "get", I guess). Also, they are more traditional JRPGs meaning that they are... harder, I guess? I dunno, I found them easy, but I also know of adult gamers who gave up on the very first boss, so I guess I'm just wrong. :P And there are the three Hack-And-Slash spin-offs that you already know about. Honestly, personally I think Cyberdimension is probably the best pick for a kid. The humor is pretty subdued there (probably the dirtiest thing I can think of that happens is Vert getting one of her little sister crushes on one of the NPCs in the game they're playing and nearly suffocating said NPC in her cleavage from hugging XD ).

Haven't seen this one recommended yet.
(https://store.steampowered.com/app/35000/Mini_Ninjas/)

It's a very enjoyable action stealth adventure game that's quite kid friendly. It's also on sale right now.

Ni No Kuni 1 and 2.

And you have been blessed by the cakeday ambassador.

For hack and slahes, try Bastion? If what I've heard of the Warriors novels is true, she should be more than mature enough to handle the bits of emotional tragedy in the narrative, though it may prove hard for her to finish. I remember the gameplay's a bit difficult.

For a non-hack and slash recommendation, I think Wuppo would be a wonderful game for any child to have. It's bright, friendly, goofy, and it's got a surprisingly deep world full of secrets to explore. I'd recommend playing it on easy.

Depending on the consoles available for her to use, she might enjoy Hyrule Warriors. Fun, colorful, zelda-themed hack and slash!

https://store.steampowered.com/app/374320/

Break them early.
Seriously though, even if this has been recommended before, Recettear - https://store.steampowered.com/app/70400/Recettear_An_Item_Shops_Tale/
My guilty pleasure game.

For a very cheap, and quite cute Zelda-like, how about Shipwreck?
If your niece don't mind a fare bit of reading, then how about Tales of Symphonia? It's got a bit of "fan service" (not much, but a little bit), and some darker themes, but it never goes overboard with them. Main issue would be the large amounts of text.

Torchlight, mentioned above, is a good suggestion. It's basically Diablo but not quite as dark. In a similar vein, you've also got the Fate series, which is basically proto-Torchlight.

Not sure if these are exactly "cutesy anime" to them or not but these are cartoonish graphics type games.

Heart&Slash

Dust: An Elysian Tail

Torchlight

Torchlight 2

Hob

Well, there will also be this: https://store.steampowered.com/app/662960/Mysteria_Occult_Shadows/
It is in Kickstarting phase currently.

Happy Cake Day, MisterWuh!

View attached image.

Happy cakeday and I would recommend Stardew Valley. I was able to play it back on my 10 year old laptop. It's also very useful for teaching kids how to plan ahead and sticking to a routine. Plus there is co-op added now.
https://store.steampowered.com/app/413150/Stardew_Valley/

Minecraft with anime mod.

may I ask why I'm blacklisted?

A few more :

Full Swing Hero :

https://store.steampowered.com/app/1060630/

Gurumin :

https://store.steampowered.com/app/322290/

Tree of Savior, free to play MMORPG, didn't like it much though... played for an hour and everything was so confusing, levels went by super fast, all the mobs were getting one shotted at once, moving around the world seemed to be through a linear path, and the classes and stats system were very odd :

https://store.steampowered.com/app/372000/Tree_of_Savior_English_Ver/

and Ys games

Surprise visit today by nieces & mum & sis, noone wanted to play, just chilling on the balcony xD

A Hat in Time
Dust: An Elysian Tail
Slime Rancher
Unbox
Gravity Rush Remastered & 2 (PS4)
Tales of Berseria (It's a little dark and can be complicated with all the tutorials constantly being thrown in your face)
Torchlight Series
Lego Series

...and pretty much every Nintendo game ever (Zelda, Mario, Yoshi, Kirby, etc)

Don't know if someone has already linked this one.

https://store.steampowered.com/app/593280/Cat_Quest/

I found it very fun, hope you like the art and concept and maybe your niece can love it too :3

P.D: Can't enter on the giveaways, seems i been BL by you u.u (Thanks anyway)

Another recommendation: Costume Quest 1 and 2

https://www.youtube.com/watch?v=IJcVECLkHvg