I feel like advertising this game as free is fairly disingenuous and is contributing to an obfuscation of the actual price tag associated with playing.
The reason I feel that this is not actually a free game is simply that using crystal energy, 100% of which is produced as a result of someone purchasing it with real money is necessary for the vast majority of the game. Any individual player may not be paying money, but his or her actions are invariably backed up by money that has been spent by another player. To me, this makes the game shareware, not in any way free.
The way prices work out now, just in crafting CE it costs between $4.17 and $3.14 US to craft a 5* item depending on how much mist energy is used. Every 5* item in the game created since the update raising crafting costs has used up that dollar amount of CE, regardless of whether or not the individual crafting it bought the CE him or herself. Figuring out the CE costs of the crowns involved or the materials used becomes very difficult and impossible to get objective numbers without probabilities for various drops and a handful of other factors, but I have been wondering for a while now whether or not the community as a group is comfortable with these prices, and whether or not people think it is appropriate to identify this game as free to play.
It's a F2P game that's monetized by microtransactions.
This is not the only game of its kind.