I love this idea! Here is a link to my other game.
I'm on this one. YOU HEARD IT HERE FIRST!
Got the growth algorithm and cell structure almost done and the gameplay mapped out.
You will grow your tree from a seed and care for it and shape it to your whim using real(virtually) bonsai techniques. Watering and feeding schedules will be determined based on seasons and whether or not the tree is in training(stress) and health, etc
The growth algorithm and display can be changed to simulate different species, but I'm going to start with just one for now.
Here is a menacing vine I grew with my algorithm: