Its roughly similar to Stellaris in that it is what you I call a "slow time Strategy game." Most might simple call it a "real-time strategy game," but its more glacially-paced (as is Stellaris) than most traditionally thought-of RTS games like, say, Starcraft. No need for high APM! Like Stellaris, you can pause and issue orders while paused.
Its honestly not quite as grand nor polished as Stellaris, but the slow/glacial pacing is similar. Sins of a Solar Empire is significantly older than Stellaris, it was originally a 32-bit game, and one could run into memory issues due to that limitation, but a relatively recent update brought it into the 64-bit era which obliterated that maximum usable RAM limitation. It can be a bit demanding on larger map sizes, but being an older game (original Sins of a Solar Empire published in 2008; Rebellion the last expansion and a standalone [so you don't need to buy vanilla Sins separately] was published in 2012), you don't need a bleeding-edge system. If you can play, say, Fallout 4 (a much newer game), your system is probably more than powerful enough for Sins.
You can buy it on Steam here:
Hope this helps!