The problem is that you need to consider of the cost of this making game too. NM paid $130 million for the investment in this game:

That changed in the past year as the Seoul-based company invested $130 million into casual game publisher SGN and launched the mobile role-playing game Marvel: Future Fight.

We don't have the exact amount of data a year ago, but let's use the data we could get from Marvel's #1 grossing game, MCoC. At 40 million downloads, they can get $100 million. Considering how players can get almost everything in this game for $10, we'll assume that there are far less whales in this game than in MCoC. Let's say that as of May 2016 (they day MFF hits 40 million downloads), we assume that MFF grossed about $70 million. Just because there is no way MFF would match MCoC's revenue because one is a generous F2P game and the other is a blatant cash grab game.

Assuming that NM received $70 million in 12 months (MFF opens 30 April 2015), then per month, they'd received $5.8, which means that they're losing half of their average gross last year.