Fascinating story and characters. The best story-driven RPG ever made.
The characters are extremely well written and are equally unusual and unique. A floating skull that talks smack, a long-dead Mercykiller whose soul has fused into his armor, a morally-upright Succubus, a streetwise Tiefling, a samurai-like Gith, a man who has been set eternally aflame, and a Modron who likes crossbows. There's a mountain of dialogue to back it up, and depending on your INT and WIS a great many responses to choose from in any given conversation. You can play the Nameless One to be as good or evil as you want, and yet the path is not always that clear... none of the trite ' save the princess' crap. The quests are far more interesting than the typical 'get this, kill that, return for you reward' type quests that are prevalent in so many RPGs. Many of the 'secondary' quests also serve to advance the main quest, which makes them more than just a loot or experience-gathering opportunity. I can't do the story justice by describing it here. Let's just say it's the best story I've encountered in an RPG since Ultima 7. The level of conversation that you can conduct with party members is unprecedented, allowing you to discover new plot information, change party members' characteristics and dispositions, and possibly even alter parts of the story. By the end, the player can get quite attached to the characters, and may wish that the story would go on forever.
The combat mechanics are pretty much the same as you'd find in BG, not surprising since it's built on the same Bioware engine. Combat can get pretty hectic, however, and the pause option is greatly appreciated. Path-finding is oftentimes problematic. Playing an immortal being certainly means that death by normal means is not a concern and later in the game the Nameless One can potentially become a one-man slaughterhouse in combat, turning most enemies into a cakewalk and perhaps killing some of the player's interest in combat. Thankfully, because of the terrific story and characters, combat takes a back seat anyway.
The sound is well done and detailed. You can hear the crowds milling around in the background, hammers hitting anvils, etc. There's very little voice work, but of what's there, it's convincing enough - characters speak out in combat, critical hits/misses, and the occasional important event.
The graphics are both good and bad. Bad because of the locked 640x480 resolution, which limits your range of view since the characters/objects in this game are much bigger than those in BG (you've got a closer view of the action). On artistic merit, the graphics are really quite good and far superior to those found in BG/IWD, which tend to look like a bunch of hand-drawn stick figures. The characters/buildings/objects in PS:T were originally rendered in 3D and then mapped to 2D sprites, which makes them look a lot more realistic and '3D-like'.
This is the type of game that you can easily play twice through from the beginning and not get bored. If you select a different style of character the second time, good/evil, strong/smart, etc., the game will look quite different.
If the concept of 640x480 doesn't offend too much, PS:T is absolutely worth any true RPGer's time.