Heartwood is a pixel-art strategy game about growing a tree. Drag from a branch joint to grow a branch, drag from the trunk base into the soil to grow a root. Keys: 1 grow, 2 thicken, 3 prune, 4 sow a seed, Tab x-ray, F photo mode, T chat on servers, Space pause and plus or minus for speed (single-player worlds), H help, P palette, M music, Escape menu. Each world keeps the day length chosen when it was made; online servers run in real time.