It is a good game, but I found that it was a bit too easy because there seemed to be very few moves which were blocked by other lines.

I like it. It's simplistic and intuitive. But honestly, I concur with @tbeakl: There are so many dots that "running out of space" is never an issue, and given that points are transferred between levels, I had 500 at the end of level 5, where the target goal for that level was 210. Far too easy. The 3D aspect also seems to introduce virtually nothing, as turning the camera only helps establish the longest possible lines... which isn't of much use anyway, as you can just spam connections and rack up shitloads of points.

My recommendation would be to disallow "double dipping": once a point is used for a line, that's it. The point can't be used for any others. Perhaps point targets ought to be reduced if that's the case, but that would introduce and element of strategy and require orbiting the camera around the cluster to establish the most beneficial approaches.

All in all though, it's not a bad game. It's pretty neat.