Hm, i haven't played a physical character yet, but here is what i think about offense and mental:

• Immobilize seems to be a bit too strong. If you want the gameplay to be a bit more challenging, either slightly decrease the time it lasts or slightly increase the MP cost.
• I never really used Quake when playing a mental character, because I did not want to risk melee. I think it would rather fit the physical character.

But i think balancing is something which should be done in a later release.

Stuns and Snares are OK I guess since some monsters will just blink near you and kick your ass : )

Are we talking about cross-class balance issues here or game-breaking issues that cause monsters to not be effective? I personally believe that most of the classes are fairly balanced (with obvious exception of the defense-only build).

Things that will empower monsters:

• Traps: Cause the player to be careful every step of the way. Traps should most often be locationally randomized (so they can't be memorized) or made unavoidable (like a monster spawn trap that goes off as you cross a bridge).
• Wandering/Patrolling Monsters: Now the Ranger can't stand back and pick off monsters one at a time. He might get flanked by other monsters...
• Monster Group Awareness: The whole mob attacks you, not just single monsters.
• More creatures should have (or be paired with) a ranged attack: Because it's more dangerous.
• Hero Powers should have a cooldown: Because spamming Quake is lame.

Things that will balance cross-class issues:

• Cause Rangers to Manage Ammo: Fighters have to manage HP, Wizards - MP. Rangers don't have to manage any resources. Their class should differ by causing them to have ammo. Perhaps a slingshot shouldn't need ammo. So they can always trade down to a lower-damage weapon if they are low on arrows, but ideally they would want to use their Greatbow...
• Create greater diversity in powers: Why do all attacks do 100% weapon damage? Why do all powers cost 1 MP? Make it so high level powers to do greater damage, but cost more MP. Make a power that hits a large area, but does lower damage. Right now, it feels like Wizards and Rangers are basically the same. Perhaps make Wizards focus more on Area of Effect powers and Rangers on single targets? (Rangers should still have area powers, but make them costly in MP, ammo, or cooldown).
• Pure-defense characters suck: Is there really any way to fix this? Probably not.
• Also... is there any way to promote cross-class specialization? Most players find it easiest to go all out in one stat rather than take a strategic number here and there. (eg. Why are there never 2,3,2,2 builds?) I think the reason this is is because powers are unlocked based on your stats. If the engine unlocked powers a different way (like specialization points awarded based on level choices or something) you might do it differently. (Imagine a blood-mage power line, which requires both Physical and Mental spec points to unlock?) Naturally this would take a great deal of code changes, would require much more room to explain than I am giving here, and is probably a bad idea.

Just some thoughts. Some are certainly better than others.

Regarding cross-class balance, the battle mage (mental and physical) build is currently pretty useless because he has to choose between having a wand and having a sword.  Maybe the wand should be equippable in the left hand as well, for dual-wielding á la Gandalf.

Some enemies should have some (stronger) restoration of health or able to use health potions. Undead bosses should be able to summon undead minions. AI should be better. There should be a bit more strategy behind a fight instead of just hitting/firing untill you win. Maybe also the showing the levels of enemies in the UI should be removed (could still be through some spell, but if the level of the enemy is at least 2 levels higher it will notice and start attacking you even from some distance).

"Undead bosses should be able to summon undead minions."

I like this. In general, I want to see more cool boss abilities that you have to somehow react/adapt to.

"I want to float the idea, though it might be too gimmicky: all magic (green or blue) melee weapons have an additional bonus. All swords have Life Drain, all axes have Bleed, all hammers have Stun."

Hrm... interesting concept! (It is rather gimmicky, like you said, but I'd certainly give it a shot). On a similar note, it might be fun to have inferior weapons have effects too. Imagine a Warped Shortbow having a small amount of angle_variance attached to it. :)

If you give longer cooldowns on ranged weapons, you might consider adding magical "Quick" versions of the weapons too.

And though I've said it before, causing multiple creatures to attack at once removes a lot of the player's ranged power. The hero can only stunlock one creature at a time. So perhaps causing the enemies to attack in packs would drastically affect the balance issue.

> Physical attacks get stronger if you chain them, building up momentum. Maybe this could be a power of certain weapon types, so broadswords have this but rapiers have a different power (but same base damage).

Combos would be awesome!  Of course, that's more animation and rendering to do, but I think it could help break up the monotony of downward slash, downward slash, downward slash...

I have to disagree a bit about physical builds. I make brawlers all the time, they obviously take more damage, and there might be some balancing that could still be used, but there's something to be said for the fact that most of the most annoying monster powers are ranged, and that if you engage a ranged monster in melee it starts attacking with melee. I much prefer to face most bosses, ice skeletons and fire antillons with a brawler than with an archer.

I did mention before though that I though that it might be useful if melee did slightly more damage, or if you could move slowly while using the block maneuver to give sword and shield a boost.