Don't listen to newbies who didn't bother spending much time on this.
The rpg aspect is very limited. You won't be grinding or obtaining thousands of gears or weapons. It means that you'll be spending the majority of your time competing in 4v4 matches. It also means that you don't need to spend much time to get the weapon and gears of your choice. There are no classes so you can be switching from weapon to weapon to find the right one for you.
Competing in melee matches is very fun. The movements are very fluid and responsive. There are 40+ weapons with tons of different move sets to choose from on the full released version in JPN and China. The En Version is still in OB so it has limited contents, but there are updates every now and then to keep up with the other versions. More specially, confront mode (4v4 pvp) is where it at. It is the best and it alone can be the sole reason why you should play this game.