This is a simple MMO cash shop style of combat game that draws heavily from the Pokemon style of combat.  The game has several layers of evonomics. There is a pool of action points that dwindles with every battle and only rises in real time.  For free players AP are capped and it only takes a few battles before they're cone.  On the pay side, the game has users buy crystals which allows them to buy a multitude of things in game. One of the things they can buy are more creature curious.  However, you buy tokens and the game randomly picks those available. So even if a player opens their wallet, there is a good chance they'll not get the one their after. So they'll buy more cystal and gamble some more. 

There is a PVP option where players can buy (or win) tickets that allow them to participate in PVP.  However this too is a big money pit.  You need 2 tickets to battle. The game picks a random opponent and often it will be someone who has high level creatures (surmised by high win ratio).  You're given the option to pick a new opponent but it costs a nother ticket. As you win battles your character gain score and rank. However you need a lot of both to get the top prizes.  However if you aren't shelling out for a lot more tickets, you won;t get past the bottom rank/score and earn a piddly reward.

Overall the game has nice graphics, decent audio and an all-too-familiar game design that is a simple cash grab cloaked as competition.  The longer you play for free, the less you can do before your AP run out, your tickets are gone and there is little point to return ...unless your wallet is fat and you like throwing your money away,