On the other hand, in my current run, I've received 5 potions of full healing in the first two stages alone, and two enchanted pieces of equipment in the first stage. This is a runaway streak of good luck, which is just as undesirable as runaway bad luck, since it negates challenge. I should expect the game to invisibly increase the Attack of all enemies so that I am forced to use these healing potions, and bring them back down to normal when I have two left.
And I would like to clarify on your rebuttal. I didn't say that a game should contain no luck, merely that luck must never be a crucial deciding factor in winning or losing. Key word 'crucial'. It's the difference between getting struck by a critical hit or status effect that forces you to change strategy to survive, and being forced to play the odds with an enemy that has a one-hit-KO attack that can't be avoided and triggers 10% of the time no matter what you do.
It's occurred to me that I've been complaining a lot about this game recently. I think I've just been playing this so much, and focusing so closely on the bad, that I needed a fresh perspective to appreciate the good. And after playing Spelunky (NEVER. AGAIN.), I can tell you that I very much have a new appreciation for the good in this game.
For any game which continues to be developed, the developer should always take great pains to remove the element of luck from game mechanics wherever it will not cause great upheavals in game balance. The ideal game, regardless of genre, is one where the outcome of victory or defeat lies entirely in the player's skill. Invisible forces should always be at work, breaking streaks of bad luck and sabotaging oddly fortunate chains of events. While the element of luck can be permitted to introduce excitement into gameplay, in the end, it is the player, and the player alone, who should control whether they succeed or fail.
Also, Polymorph should not transform a creature into the exact same creature type. (I don't mean it shouldn't resist, I mean the spell hits a Crossbow Guard, and transforms into a Crossbow Guard.)
I just got 3 Leather Vambraces in treasure chests in the first stage alone, and a fourth in the second stage. I think it would be nice to hard cap the number of times a piece of equipment may be found in any given stage to 1, and 3 in the entire Act.
Suggestion: Some skills should have slight tweaks if used by different classes. For instance, if Pugilist finds Fireball, it should change to a Physical skill and be renamed "Hadouken" (Or "Kahouden", or some other copyright-dodging name.)
Shieldmaiden, that would completely undermine the core aspect of a Roguelike. In these games, it is always impossible to level-grind; you must rely more on your wits than your raw power.
Mostly I suggest this because I notice that the Speed stat is too powerful and important compared to all other stats. It governs far more mechanics, and is more vital to your success, than any one other. It makes some decisions trivial as a result; for instance, I never pick up Bonecrackers or Earthshakers, because no matter how much damage they offer, their speed penalty always makes them worse than useless.
Recharge rate for skills should be a product of time, not turns taken. A character with lower Speed, while allotted less steps per minute, should still get just as many skills off per minute. (And the skills should displays seconds remaining to recharge, instead of turns.)
If I might make a suggestion, I think it should be enough to just touch the fish with your cursor. Having to click them constantly gets tiring, but waving your cursor across the tank is much more relaxing.
Even after playing this game for over 116 hours, I'm still not sure whether I want to shake hands with the creator, or punch his face. Probably both at the same time.
As a Thief, if you are being chased by an enemy, cast Glide, move out of sight, and use Shadow Walk, the enemy will still be able to see you with Shadow Walk cast, until the moment Glide wears off.
 "Bobby the fish"){kind=icon}
 "Cardinal Quest 2"){kind=icon}
 "Idle Tree"){kind=icon}
 "The Cave of Ātman"){kind=icon}
 "Tale of Scale"){kind=icon}
 "Tower of the Archmage"){kind=icon}
 "FISH Inc."){kind=icon}