Here's a trick to playing this game, fully upgraded your unit after playing it like for about 10-20 minutes, then come back in the next 12 hours to a week. Just like that, you make progress than when you actually play the game with 1000+ level from afk exp gained. It kinda sucks that I feel like this game is a downgraded version of 99% of every idle games in google play store right now, especially when the p2w aspect is utterly useless in this game. I find it even more annoying than playing a gacha game even, especially when there aren't any game modes, resource gathering, or other class to character changes for it to be worth to actually spend real money on this game.