I think there's a lot of interesting strategy in this one. It's pleasantly unclear what immediate implications there will be whenever you place single stones, particularly in the opening.

It feels like a single stone played half way through can be good _only if your opponent will have to play a single stone in response at some point._

Yes, if the opponent starts growing, more often than not one will have to fowwow suit. If in that case the distribution of one's stones is unbalanced, the opponent may carve out big pieces of the pie. One must either use that or face that

'Only' may be a bit strong, but most of the time yes. But a single is also a source for additional growth, and if it can manage the quest for life it starts paying of a few moves later.

As in Go, there's quite often a difference between the 'general' and the 'specific'.

I think that's where the strategy becomes interesting. Evaluating the difference between following suit or expanding is complex, particularly as the territory potential of groups is variable, so even though you may have more groups and thus more stones to place per turn, that doesn't necessarily correlate to the expected total net points of (group * moves) due to the limit of expansion that each group has.

The fact you then required a set number of multi-moves to kill it guaranteed the life in the top left corner as well, which was something I had been struggling on how to achieve without having to use a single-stone move.

The quest for life is actually remarkably hard for an invading stone. Not least because your opponent can make go-nonsense moves to kill it (such as contact playing a 3rd line stone on the 2nd line). Because the typical moves consist of extensions, it's remarkably hard to place killing moves without losing the momentum of multiple stones, and as your opponent has other groups around if its an invasion, that means you end up making less stones for your group per move than your opponent gets towards killing it and removing eyespace. All of which increases the importance of well placed early stones.

I think strategically I'm still a fledgeling at this game, but the progress so far is intuitively strengthening my opinion that territorially placed early stones are more valuable than influential ones. The nature of the extension game makes it even harder to quickly mark out central territory than it is in Go I think.

Well, this has certainly been fun