For fans of the game, Atlantis is most certainly worthwhile. In playing Atlantis, I realized how far removed I had become from this ARPG franchise, and it was good to revisit. Quality new content as well as immediately-beneficial time of life upgrades to the game in general make Atlantis easy to recommend.
A surprise expansion that’s a fun romp across the Mediterranean with a wide array of new toys to play with and some subtle but useful changes to the original game. No new mastery and a handful of polish issues are a shame but it’s a great reason to go back to Titan Quest.
Atlantis isn't necessary like the first expansion/Anniversary Edition. It's also not as interesting as Ragnarok, which adds the Rune Mastery, thrown weapons (I love thrown weapons! They're like having an automatic pistol + a shield.), and a HUGE new act.
The extra Mastery levels are nice, as I usually have both at 32 by the time I've killed Hades. There are a lot of new items too (check out the online TQ Database).
I'd say buy it if you love Titan Quest, are a completionist, and it's on sale for 50% off or more.
ETA: As far as when to play through Atlantis, I'd say do it during and after Act 4, but before Ragnarok if you can. The item and monster levels are a bit lower than Ragnarok. If you do Ragnarok first, Atlantis won't help you level up/gear up much, IMO.
As far as glitch complaints go, I find that both Atlantis and Ragnarok suffer from frame rate drops and minor bugs much more than the Anniversary Edition. It's still totally playable, though.
Note: I also play on the "fast" setting and have a character with heavily boosted movement and attack speed, so that might be causing some of it for me.
When Ragnarok came out, there were concerns about how underdeveloped (in terms of bugs, mostly quest-related) the expansion pack is. But that's nothing compared to Atlantis. First of all, I do not find any major advantages of the add-on yet, it costs as much as the full add-on, and offers such mediocre content that it's a pity that it meets such a great title as Titan Quest.
The expansion pack is embedded in an opponent's level cap, which is too low for most even after completing Act IV. Atlantis is supposed to be something between Act IV and V in theory, but it doesn't present a challenge unless we start it right after killing Typhon.
It's good that there are new opponents, not refreshed antiques, but I have some deja vu to Grim Dawn.
And another "novelty", that is the Tartarus mode, is a complete rewrite of the mode added in the "Forgotten Gods" expansion to Grim Dawna. At the same time, this one often bugs and can be terribly lagged.
We don't even get a new Championship like Immortal Throne or Ragnarok did, but new skills for the old ones, which are at best moderately interesting and usually simply unnecessary.
The locations are nice, especially thanks to the alleged graphical improvements, but in practice they are difficult to enjoy if the game is constantly having problems with frame stability and other changes resulting from these "improvements". As in Ragnarok there were problems with optimization, here it is in a dire state.
The only thing that has made a relatively good deal is the dealer-dealer who sells random loot, which is the only way to get rid of the millions of gold we accumulate for no matter what. Still, I would prefer (since they are already copying ideas from Grim Dawn in a clumsy way) to introduce an illusionist who would change the look of our inventory ...
The game was released last May (2019) and so far nothing has changed. The released add-ons are in a deteriorating condition and unfortunately the fears after the problems with Ragnarok have been confirmed. At this pace and with such a tendency, the next addition will cost PLN 80 and (apart from the background in the menu) will add an "act" for half an hour of the game, which will be impossible to complete due to bugs and technical problems.
SummaryThe Hero meets an explorer that is searching for the mythical kingdom of Atlantis, and together they set out on a journey across the western Mediterranean. The key lies in the legendary Diary of Herakles, rumored to be in the Phoenician City of Gadir, but their journey will take them beyond the edges of the known world...