Stone Walls with Bone Spike Upgrade

[SuperDave]

Mid to late game when you seem to have ample supply of both large stone and bone, seems this would be a good way to consume that resource overflow and add significant durability to your front lines.

[SerBucky]

That ample supply of large stone is going bye-bye in update 3 because roads will cost 3 small stone per cell lol.
But I agree, upgraded spikes would be awesome eventually - maybe once trees regrow though.