Idle parts of this are, waiting 24h for guild loyalty cooldown, and hero exp, and waiting for quest. It is fun if when you play litlle bit every day, to get daily card, diamonds quest goals and use 30 mim bonus after guild loyalty. As guild loyalty is min 10x upgrade for guild bonus, with 24h cooldown, there is no point idle for bigger normal guild bonus, also 30 mim gold membership speed up bonus rebuilding after loyalty. ps. Gold membership is only good for rebuilding bonuses after loyalty reset them 0. As progress will stop with normal reset very fast, it will give nothing compare to artifact upgrade, purple manna ball bonus, and shop pernament upgrade.
Seems to be little hard but after few run I started to make notes of health wells, learn warrior tactic and fairly easily run to 9 floor every time. With difficulty spike, it was best to switch between optional dungeon and next main floor to gain exp, but after beating arcane tower, and beating few monster in ice cave(to risky with cold mechanic to clear it), rest was just to be caution and use stair often.
Impossible badge is too easy, or I had good RNG? I took me two tries to beat final boss. Auto revive get me past one of double nuke, second try i was stun nuke them into oblivion). (ok, 4 tries to win I also died to dragon because it could resurrect heads and then once before bone dragon, trying to stack buffs before fight.)
Best updates. Before armory, after unlocking 6 heroes soon you had 6 ranger team with only staking exp and dmg. You only try different build for fun, rangers were fastest to progress. Also unlocking new layers early for few points was not worth it, you need to grind a lot of point on layer then made first reset for reasonable progress. Overkill made warrior useful. Second armory update was brilliant. It made every class and stat useful until ~52 floor. Then enemies started scale to fast to make some of tanking build useful. Overkill and maybe paladin for flat multi. Still full dmg. Floor inflation changed that, you can really try different build and changing them is helpful even after unlocking 8 layers. All build and class had plus and minus. Progress fill more natural now, there are ways to back up after first prestige 3 point on L8, and it is not too fast, you need to climb, but beginning is less painful with armory and build changes. It fills more natural and easier to control.
Because stat multiple between layer and enemy never attack first, game becomes exp and dmg as only important stat later. So if Hp of heroes is lower than enemy, enemy should have possibility to attack first on Higher floors. If that also button to turn on healing between floors. Secondly over healed heroes should be buffed and have more dmg. This will increase important of remaining stats
Easy badge you can just with getting bigger, and dodge mine when you are small until you get two good super power on the screen. You can get badge with few tries
 "DPS IDLE"){kind=icon}
 "Idling to Rule the Gods"){kind=icon}
 "Rogue Fable III"){kind=icon}
 "Epic Battle Fantasy 2"){kind=icon}
 "Particles"){kind=icon}
 "Incremental Adventures"){kind=icon}
 "Bubbles 2"){kind=icon}
 "How Dare You"){kind=icon}
 "Mighty Party"){kind=icon}