I'm personally enjoying Star Rush a tonne.

Now I realise the opinions on here are going to be skewed towards positive considering the site's content, but I genuinely think that ND have taken a step in the right direction.
So here are my thoughts on it, if you don't feel like reading it all, there's a summary at the bottom.
Firstly, because there's a lot of single player content, especially if you want to complete everything.
There are lots of really fun and interesting minigames.
The different game modes are amazing! I think Coinathalon and Toad Rush are the best bringing a lot of new stuff to the table and just being plain old fun.
Having the party guest software is an absolute blessing, no more limited download play is awesome.
The game uses everyone having their own screen super well, both in minigames and on boards.
Single player difficulty is tweaked juuust right, I'm actually having trouble with master level CPU's, which is more than I can say for Island Tour.
I certainly enjoy it more than Island tour, and foresee myself playing it for a lot longer.
There are a few things I think could been improved.
The explaining of certain game mechanics on boards, especially for multiplayer friends who are new to the game and have no idea what is going on. I've found I have a hard time explaining every rule, and I don't want to force them through the tutorial boards (or play them myself).
Landing on another player's space is annoying, and because 2/3 of the duels are luck, players will often lose partners even if they needed them more than the other players. I've had too many games where one player has max partners and everyone else have 0/1 because they keep losing them to the one player. These should instead be more likely to give from the rich to the poor.
Not having partners can cripple your experience. If you don't get one by the second boss, the chances of you getting one are very low, because you're already not moving much. Once you're moving slow you don't get much done and have a bad time.
Overall, I find it's just very enjoyable. It does require some teaching if you don't want to force everyone through the tutorial stuff, but after a practice game everyone will have a blast (unless they're losing

). And for those without friends they can force into playing it, it has PLENTY of content to keep you going, especially if you want a super star rush on every level.