9.9/10
If there was a fighting game where everyone returns and anyone can join the fight, this would be the best example.
For newcomers and younger kids, this is a perfect introduction to the series, and what it's about. For veterans, this game is a great way to see what combos they can create with the returning characters.
With the 5 DLC fighters, including Joker, Dragon Quest Hero, and a certain Bear and Bird duo, all players can get a chance to be introduced to the worlds the characters live and fight bad guys in. This adds variety to the game too.
The Story Mode and Spirit battles are a perfect mix of challenging and easy for players. Spirits are an interesting addition to the world of Smash, since you can use them in battles.
Lastly, Online Mode. It's okay, but on shared content, kids may find some inappropriate stuff, and there need to be more admins to detect things like this quickly.
Overall, the game is mostly perfect for newer and older players alike.