For reference it took me around 7-8 hours to complete Super Mario Run with all pink coins set, some purple coins set and the first world black ones.
I didn't even touched yet world builder and the ghost challenges basically.
The ghostly levels are simply brilliant, I wish there were 20 more levels of those.
A warning.
Tickets are capped at 99.
So if you like me just play the single player portion, you will waste a ton of tickets because the game simply delete everything above 99.
I 'lost' at least 20-30 tickets (all world bonuses), before realizing.
No biggie but keep in mind that (you can replay each boss at will for two tickets).
I really recommend the game, I still have so much to do, but if you cruise the levels without considering the coins it's a very short one.
That said, getting the coins set is really fun, at least the first two.
Black set....I'm still in the fence about them.
It's nice and hard but very often at first mistake you just reload the level knowing that you won't complete the set no matter what you do, because some coins are reachable only if you hop on a enemy in a certain position.
If you miss it you could have killed it or it moved, and they don't reset if you rewind time, which is an odd decision in a almost perfect game.
I hope they will add new levels already, it's really super fun imho.