There are lots of posts speculating about a planet (or whatever) where life evolves intelligence and goes on to produce technology, under different differences lacking something or another that is available to us.
Without thumbs, without metals, without vision, in a different atmosphere or liquid or vacuum, as a vegetable, and various other differences in environment and physical attributes.
For mental differences, I see one question about mindset being affected by lack of pain, but intelligence is already imposed by design.
When I see Vulcans portrayed as emotionless, I sometimes wonder if that's plausible, as emotionless humans do exist and we call them sociopaths.
Rather than without any emotion, I'm postulating a species that has an internal self-awareness in the same manner that we do, but is missing some specific emotions (relative to our situation).
In particular, Love and related social emotions evolved because we have social groups and close families for raising children. A species without emotions for individual attachment would have no concept of grief or heartbreak, and would find our idea of love to be maniacal.
I'm supposing this is due to lack of or profound difference in social structure, at least in the recent evolutionary past. How could such a species cooperate and not kill each other off like solitary territorial species, to develop a civilization?
Note that it may have different emotions, including something we have no concept of. You can't explain the feeling of an alien emotion, but can specify the evolutionary meaning and how it acts as a motivating influence.
(I have one idea, but I'll wait and see what others suggest)
Bonus: what would it do for poetry and art, seeing what drives ours? Or would that be missing as well and have a deep influence on the culture?