Cute, but the set of quantum gates is so limited that simulating them is trivial, and in particular you don't need to sample multiple iterations to estimate the probability distribution because you already know it exactly.
There's a browser emulator that does up to 16 qubits. Assuming half-precision floats, the Commodore 64 could do 6 in just the RAM or 7 if you use a floppy for extra storage. I wonder if there's a more compact way to implement radical integers; a quick search doesn't yield anything.
Edit: Storing them symbolically would probably be the best way. If we assume most figures won't have more than one layer of nesting I wildly guess you could store them in half the space and add a qubit as a result.
If you're good with linear algebra it's not the most complicated thing to implement. It gets exponentially wider as you scale up but at it's heart it's still just basic linear operators on complex vectors.
Or, alternatively, since they are already making the (reasonable) compromise of working with a restricted gate set, they could expand their gate set to the Clifford group and then use the CHP algorithm to scale to much larger systems.