Time for a quick update via Steamspy, a few days into the Steam Summer Sale:
Tyranny owners - 204,355 ± 12,470
Torment: Tides of Numenera owners - 125,282 ± 9,764
Planescape: Torment: Enhanced Edition owners - 32,466 ± 4,971 (released Apr 11, 2017)
Expeditions: Vikings owners - 31,470 ± 4,894 (released Apr 27, 2017)
Here is a little update on a few titles, 2 months after my last post:
Tyranny owners - 240,505 ±16,739
Torment: Tides of Numenera owners - 150,696 ±13,251
Planescape: Torment: Enhanced Edition owners - 45,666 ±7,295
Expeditions: Vikings owners - 43,230 ±7,098
Tyranny continues to sell better than Torment and has moved up one tier, firmly in 200k+ territory, though it has slowed down a bit. With the expansion coming out in a few days we should see an increase in sales, especially if there is a significant price drop to mark the occasion.
Small side-note: Icewind Dale Enhanced Edition has now surpassed Torment according to Steamspy - current owners are 154,654 ±13,424.
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Some more data below, starting with the 100-200k tier:
Hard West has surpassed 200,000 owners - currently at 218,890 ± 15,969
Shadow Tactics remains under that mark - currently at 180,531 ± 14,503
Expeditions: Conquistador - currently at 161,960 ± 13,737
The Banner Saga 2 - currently at 153,741 ± 13,384
50-100k tier:
UnderRail has surpassed 100,000 owners - currently at 114,468 ± 11,549
Battle Brothers has surpassed 100,000 owners - currently at 100,769 ± 10,836
Age of Decadence - currently at 95,593 ± 10,554 (but according to devs it is over 100k as well, so +1 tier too)
Paper Sorcerer - currently at 92,244 ± 10,368
STASIS has entered this tier as well - currently at 51,145 ± 7,720