The Therapist Gamer

This free Vita game takes a similar approach to many mobile games.  It uses the following structure: create monster, wait for it to generate funds, use funds to build or upgrade monster, wait for upgrade or gestation, make more money with your better monsters, wait; repeat 5,000 times.  I normally find these games unbelievably un-fun and stay far away from them; the skill required basically involves waiting or spending real money - neither of which are real skills.  

 

However, this game has one main thing going for it - all of the monsters you create (breed and hatch, actually) have a different musical part in a song.  I found it tempting to get more monsters in order to hear more.  There are also multiple levels, and each monster will have a different tune depending on which level they're on.

 

For the life of me I'm not really sure why I got sucked into this particular game, but I did.  It's a little embarrassing, actually!