If you're seeking lots of special moves or evolving gameplay mechanics you won't find them in "Katana Jack," but it perfectly captures the feel of ye olde single-screen arcade platformers. This is definitely a title you should snatch up if you're looking for a simple action game you can play in short spurts from time to time.
"Monsters & Bones" is undoubtedly one of the most unique action puzzle games in the $0.99 price tier, but also one of the most difficult, and not always for the right reasons. View it as you would building a model ship: all the ways you can suddenly fail can make the experience more tedious than fun sometimes, and yet you can take real pride in mustering the concentratin and attention to detail necessary to succeed.
Finally: a game with Doodads! "Mystery Ball" could still benefit from a little more polishing, but it already offers some great logistical challenge and its environment altering concept never gets old.
This action adventure title sometimes jumps the shark in terms of difficulty, but on the whole it's a thoroughly enjoyable exercise in defying gravity. If the fact that the character has Weegee's eyes doesn't win you over, chances are its depth and breadth of content will!