-- 1, 2, 3, 4, 5, and 6 all control the placement of your finger on the fingerboard. -- Q, W, E, and R all control the lengths of the notes. Note names and lengths are displayed on screen. Click the button that says arco/pizz to change whether you play with a bow or your fingers.
I made a Virtual Cello roughly 2 years ago from when this was released, over time it has gained a lot of feedback (At the time of writing this it is at 3,960 views!). It also stated that the primitive cello I had created was the best I could make, which I have proven wrong here.