I'v played my fair share of clicker games and this one is still the best one. Surprisingly it needs some light problem solving skills, basic math skills etc. to make useful progress later on.

- 3-layer prestige system (1. Heroes (buffed/paid by gold) / 2. Ancients (buff Heroes) / 3. Outsiders (buff Ancients). Ascend (soft reset) to get stuff to get ancients, transcend (medium(?) reset) to get stuff to get outsiders.
- Real exponential growth. You will understand that later on 400% or 1000% increase in damage is pretty much nothing(5-10 more levels).
- Meaningful progress(faster and slower paces too) throughout the game, there are always new heroes to get to boost your progress(around 50 in total) or get back to older ones and level them up to get bigger bonuses etc. Serious end game grind starts after level 1 million.
- Idle, active and hybrid styles to progress, depends on patch which one is the most beneficial, just try them out by getting different ancients and leveling corresponding ancients. Outsiders are buffing ancients and are a huge (exponential) boost to your progress.
- Couple of other mechanics which I won't go into details here like mercenaries or autoclickers, just find them out :)
- Free to play, and you make your progress without spending a dime (it's also really bad value to buy rubies (in-game currency) with real money). You get enough rubies in-game.

Basically nothing bad to say about this game, its free and its probaply the best clicker game out there. At least one of the very best. Oh and graphics are nice and its actually interesting to read the "lore" the heroes have ^^ You also might be able to listen sounds and music for the first thousand or so hours, after that you just need to mute the game :)

And no, I don't play anymore, I stopped at lvl 1 million. I value my life.