A Game I Genuinely Keep Playing Consistently

There are no events or time quests... but I've been playing for years and I'm already at level 7320... Honestly, the further I get, the more they seem to intentionally make it hard to clear. It's so difficult to clear that it now costs around 17,000 coins per level, and sometimes it takes several days to clear one level, which eventually leads to in-app purchases. Still, I can't stop playing.