I played the Destiny of Spirits Beta for about 1,5 hours today. (tutorial plus about an hour or so)
i have to say it is ok.... but since i am playing magic the gathering i miss the depth of combat.
weakness/strenght against elements is only in one directions. you have 5 elements, and it's only like: water beats fire but not vice versa.
there are no skills or whatsoever for "you", the destiny master. so you only customize through the spirits. i haven't found out if they can evolve.
you level your spirits merging them. so you take your level 1 creature and merge it with two other level 1s and it gets level 3, increases stats and so on but it stays the same creature (i guess there will be some combinations that evolve to something new).
payment model seems to be hm, dunno. if a spirit dies you either wait 30 minutes (you can replace it with another spirit) until it revives or you pay.
you can gather spirits through fights (doesnt happen a lot), summon them with points that you gain from fights, or you summon them with real money. i guess this guarantees to get a uncommon spirit, while the "free" option gives you mostly commons.
i hope you can at least evolve the spirits for some cool combinations.
but the combat itself is pretty boring. like a real time rpg. 3 vs 3.
i definitely recommend checking it out. maybe the game gains sooome depth later. i am still waiting for ANY free to play game. no problem with paying a small fee for several stuff, but the games simply lack content mostly.
must-have-list for platforms i don't own yet:
WiiU: Donkey Kong
XBone: Dead Rising 3, Ryse