I've been playing the game since around the end of March now, and it is surprisingly addictive for an idle game.
One issue I do have is with the advancement/difficulty curve, which becomes extremely 'EXTREMELY' steep as you approach mid-game. Even with a 2,350,000% damage multiplier from white orbs, all Hell Buildings at lv.4, several hundred chest items, a black orb and all monsters levelled to between lv100-600 I have still not managed to clear the second map, which I am gradually chipping away at a snails pace.
--RECENT LAG ISSUES AND FIX--
Recently the game was hit by some pretty severe and crippling lag, and judging by some of the previous reviews I am not the only one. I believe this is due to some background advertisement script because re-enabling my adblocker completely stopped all the lag and made the game playable again (you will still receiving rewards). If Berzerk Studios can fix the issue, I will gladly disable my ad-blocker again, as I think their ad/reward system is pretty cool and fair. However, however as things are, the lag is so bad the game has become unplayable.
--BLACK ORBS (SPOILER)--
Probably not much of a secret any more, but I have finally located my first Black Orb. For those of you interested they drop from secret super bosses located on each map. The first one 'The Wizard' spawns if you fully clear every area on the first map, and then use the tier 2 portal (the x2 orbs one). Using any other portal on any other world will prevent him from spawning. Be warned, he is no push over, but the black orb reward is pretty sweet (50% bonus to total DPS)