Wow, this game isn't even subtle about being pay to win after the first chapter. No way to farm gems (or gold in a reasonable amount of time tbh). Incredible difficulty spike at the beginning of chapter 2, no way to get better cards via RNG, some Items to lvl monsters up apear to be shop items only,.... if you don't want to invest ALOT of money into the game don't play.
Ok, Please redo the achievements, they are just not practical. And with that I mean, that they are actually impossible to do. E.g. the collect 7.500.000 Resource tokens achievement would take over 14 days of constant, active game-play to unlock if you collect 6 tokens per second... which already is more, than you can actually collect in that time. And, if you kill 25 enemies in 1 sec (a ridicules high number, even if you go to a map where you one hit enemies) you would have to play over 1.2 Million years to get the last 'Kill them all achievement'. So unless there are fleets with millions of ships that can be insta-hits in later levels (in which case I apologize for my rant)the achievements are unnecessary and don't feel rewarding at all.
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 "Soul Reapers"){kind=icon}
 "Death Squad"){kind=icon}