It's basically a card collecting game where cards are similar to pokemon where they have different elements, types, skill sets, rarity. You hunt and collect more cards to make your current cards better. The storyline/questline is really straightforward and mostly time consuming but the funner aspect is the coliseum where you use your deck of 10 cards against other players and try to get a higher rating every week.
The main strategy with this game is which cards you put in your deck, how you arrange them, how you build them, etc. The reason for this is when you use your deck, you have no further interaction with the outcome of the battle as the cards will fight each other automatically following AI (for example, A1 will attack A2 and kill it, then B2 will come out. A1 could attack B2 again if it's fast enough, otherwise B2 will attack A1. The skills they use and buffs/debuffs they use can be predicted but you can't actually tell them what to do at certain situations).
All in all it's a fun game. It can be seen as a boring, time consuming game where there's some luck involved getting your deck stronger but for me it's addicting and I play it every day.
Does anyone else play it? And if you don't play it, and you want to try it out, it will ask you to enter an invitation code. If you use mine BW65189 we will each get a nice bonus for it and it will be a good help to starting out players.