Having played this game quite a bit, I feel I can now give it a pretty fair review, and so here it is:
It is a very faithful interpretation of both Gygax's original Temple of Elemental Evil, and the 3.5e ruleset, which scores it major, major geek points. Unfortunately, the damn thing is so full of bugs (computer bugs, not giant centipedes) that sometimes you find yourself doing stupid, nonsensical things just to get around problems with the game.
Case in point: neverending spell effects. This bug was supposed to be fixed in the patch, but they lie. Expect at least one member of your party to be permanently under the effect of, say, a silence spell if you're lucky. I was not so lucky, and at one point the party barbarian was the unlucky sufferer of a permanent spike growth spell.
In case you're not familiar with spike growth, this is a ranger/druid spell that makes thorny vegetation grow in a 30' or so radius. Characters walking through it must make a saving throw or take a small handful of damage, and get their movement rate halved.
Given that the purpose of a barbarian is to run around the field soaking up damage, a bug-permanented spike growth effect just about completely negates him! He has a lot fewer hit points than he should (because he takes damage every time he moves in combat), and instead of moving faster than anyone else on the field, he moves the slowest! Thus, drastic measures were called for. Checking the Atari website forum, I found that there's only one solution to the problem: get the character killed and cast raise dead on them. Gah.
So, in order for my barbarian to be useful again, I had the party gang up on him, slaying him, then had the cleric raise him. What kind of sense does that make? Storywise, none whatsoever.
There is also a problem with NPCs and their inventory. NPCs join the group for "a share of the loot," okay, no problem. But what that boils down to is that when you're looting chests or slain monsters, the NPCs grab a random bunch of junk before the player gets a chance to see what's there -- and then won't do anything with it. I picked up a bard along the way who is now carrying something like three pairs of boots (including one set that's from plate mail armor), a quiver of arrows but no bow (I gave him a bow early on but the idiot sold it), and a bunch of scrolls that he can't cast spells from. This, I assume, was done to prevent players from robbing NPCs blind, but it's a lame solution. Even lamer is that when the NPC's inventory is full, they will start dropping items on the ground with a "do not remove from inventory" bug on them. So if you have one of your characters pick it up, you'll never be able to sell it! That's just plain sloppy programming.
My only other real gripe with the game is that most of the town quests are dull as dirt, and interesting NPCs are few and far between. What's particularly annoying to me is that a lot of the most interesting recruitable NPCs won't stay in your party -- or make life hell for you if they do. I picked up a hill giant follower named Skorpp who was a lot of fun -- except that none of the townies (including the merchants) would talk to me while he was in the party. D&D doesn't work very well without shops in town to work with!
I picked up a wizard in the Earth node who was insane and believed the party leader was a demon. He wasn't much of a follower (a 5th level wizard who didn't know any spells!), but hand him some wands and scrolls and he was useful. More importantly, he was fun to talk to ... but since his goal was "escape the dungeon and get back to civilization," he ran off the moment the party went back to town. (I knew he was going to, and retrieved my wands and such before it happened ... but I was still sad to see him go.)
Oh well. :) It is still fun and very cool to play a good, turn-based D&D license game; the fact that it is 3.5e and such a faithful rendition of ToEE makes it so much the better. I'm enjoying playing it -- but I'll also be glad when I'm finished!
PS: Wait, I forgot one important gripe! My ranger has no control over his wolfish animal companion. Can't teach him tricks, don't have input in combat, etc. That would be okay if the animal's AI was any good, but it isn't. Invariably, the wolf goes dashing into the middle of any combat and attacks the largest, most invulnerable, damage-dealing monster. It also seems to get bonus points for putting itself right smack dab where the party mage was just about to drop a fireball or other area-effect "empty the room" spell ... which of course means I get to choose between winning the fight, or not killing the animal companion. I've taken to having the NPC bard, who is often only moderately useful anyway, use his bardic music fascinate ability to hypnotise the wolf at the beginning of combat to keep him out of harm's way. Either that or locking the wolf in a cleared room before going off to face the next room full of monsters.
Again, dumb designer decision. Le sigh.