[jkey]

[one of the co-authors of the game here] What you got is CFR 4%, which is highly plausible. As in reality, what you see as cases, are just confirmed cases.

IFR could be calculated only from the explanation only at the final screen, where the actual number of infections is estimated (it's several times higher than the confirmed cases)

We could legitimately say that in your game, the number of infected people was not 2.1M, but, including reinfections, there were up to 6.2M infections, according to experts’ theories. The game and your results only register the officially recorded infections (based on test data).