Cosmic Express comes from Draknek Limited. They came out with A Good Snowman is Hard to Build from about 2 years ago. That was a great game.
The object of this game is to find a route that will pick up the orange & purple people and deposit them in their boxes. If you played RGB Express from 2.5 years ago, you'll get the idea.
Cosmic Express definitely borrows the concept or RGB, but that's okay.  In many ways, this game is has some good innovations like wormholes.
Most importantly, Cosmic Express is tough! But with enough fiddling, they're all reasonably doable.

There are approximately 120 levels.  I've done about 40.

$4.99 is reasonable, considering it's led to about 4 hours of fun, so far.

https://itunes.apple.com/us/app/cosmic-express/id1152474226"mt=8
https://cosmicexpressgame.com/
https://play.google.com/store/apps/details"id=com.cosmicexpressgame

...