If you’ve ever been into card games and have some time to kill take a look at Kongai from Kongregate (an online gaming service). Kongai is collectible – but you get given a new card for winning matches and/or by completing challenges on other games on Kongregate. There are only 50 or so cards - most of which are characters. You take 3 characters into battle and then use a scissors, paper, rock combat system to render your opponents characters to dust.
linkage: play kongai