It's actually a good game. Worth staying long as you got the moolah to stay strong and not left behind.
F2P should be a doable experience long as you got a friend to play with to make it bearable. Playing it alone is kinda lonely not unless you want to follow the story then the game itself is good in that aspect.
The sounds selection in every menu is quite good taste. Two-thumbs up to music team.
The game is good gameplay wise. It has Auto-play. Good character design. I'll missed Echo and Shiro, I guess. The game will stay good long as they don't jump into ai bandwagon. So, good luck and keep it up.