Hello, I have just given your game a try after seeing Paul Soares Jr's YouTube video of it. I'm really enjoying it and quickly lost track of time! Here are a few of my observations:
On my first try, I found that some of my buildings were not working. I believe it was because I had blocked them with other buildings. On my second try I spaced them out more and everything went more smoothly. I would suggest somehow displaying on the blueprint what direction it is accessed by, so we can know to rotate and position them better.
I managed to get a pretty big raft going and started building up a second floor. I found it fairly limiting with the pillars only supporting 5 tiles above them. As it is, it would take quite a few staggered pillars to support a second floor, and by that time you've already placed your other buildings on the bottom floor. Deconstructing some things to make room is fine, but you'd have to deconstruct and rebuild quite a bit when you have to place so many support pillars. Also, is there currently a way to hide floors above your currently selected one? It very quickly becomes impossible to interact with anything on the bottom floor.
Finally, I think there should be a way to cancel a placed blueprint before it gets built. Several times I accidentally placed something facing the wrong way or I didn't realize I was missing some of the ingredients, and the blueprint was stuck there taking up space on my raft.
Anyways, I look forward to seeing the game develop further.