Here are some things I noticed playing my strongest warrior on impossible difficulty:
The character is level 600 with 1,194,829,562 score, 10,946 kills, 201 champions slain, and 1,080 treasure chests.
99% of time spent in quests or dungeons.
The character has ~21k strength and 25k hp. This costed ~52,834,160 gold.
Able to 1-shot the Cow King with a Power Attack. Power Attacks do 25,500±200. Berserk Attacks do 53k±10k.
Farming the Secret Dungeon as fast as possible (with 15k strength) yielded ~200k gold/minute.
71,987,650 xp is required to hit level 600. 359,701 xp is required to progress from level 599-600.
The strongest enemy in the game is a champion Demonic Treasure (no unique name).
It has 50k health and does as much damage as the Cow King (<2k on impossible).
It is EXTREMELY rare, because it requires a chest encounter, a Demonic Treasure in the chest, and the Demonic Treasure must be a champion. I estimate the odds of finding one are less than 1 in 20k encounters.
A couple things I have noticed: Not asking for free stuff is the best way to get it. No one likes begging and people will give you items if they feel you deserve it. Tier 7 weapons and armor and tier 3 rings an abilities and below are mostly worthless. A level 20 character (or a good player at level 10-15) can kill gods with little or no help, making these items valuable only if you will equip them. Trying to sell them is really not useful because no one will pay currency (stat potions) for them, meaning finding the right deal will be a slow process.
requires energy? sounds like Fantasy Online, Dream World, Facebook games, etc, which I don't like. I think I will pass. The concept of limiting the consumers play time and pushing them away from their game is lost on me.
at 4000 (yes, 3 zeros) weak firebolt never hits below 4000 (1x), firebolt never hits below 7200, ice spike never hits below 8000 (2x), inferno never hits below 8500, and fireball never hits below 9500 (against the denizens of the most difficult dungeon). Oh and fireball has never hit 13000.
the distance between 1st place and 2nd place on highscore for impossible is sad. It isn't really that difficult if you know what you are doing. But the number of highscores I have besides that is actually pretty low.