It took me like 5 tries to finally beat the CPU, difficult. Sometimes you would get caught on the dice as it moved, however, and it was frustrating to get stuck. I really like the idea and nuance to the game, as you're thinking in 3D space, trying to get to slightly higher numbers, even if they're not 6. Maybe dice with different sides will force you to not stick to one strategy once you find it, and could adjust for difficulty.
Anyways, cool idea and fun visualization!