"Feel Good" games?

[Chutzpar]

Usually if I want to chill out I play games where rounds/levels are short and you can dip into them easily. I've just started replaying Modnation Racers again, and while some of the later tracks are evil, the earlier ones are pretty good to just mess around with for funsies. The customisation is really excellent, too- it's quick to get into and surprisingly versatile.
Only problem I'm having recently is not being able to find many people online to race against, but it's not like there's a huge difference between racing against the computer and racing online anyway ;v

Audiosurf's pretty good too, if you play some artists like Mr Scruff or Bonobo and use one of the mono characters, it's pretty chill without being barren.

Oh and if you can play LBP or Katamari without your face being paralysed with pure joy you probably don't actually have a soul. They're not necessarily chill, but they've both got a lot of charm and just make me feel really great about everything.