On the contrary, the game is realistic in this aspect. Czechia was basically never able to close the borders so tightly you would prevent "all imports". What "closed borders" meant in practice were tens of thousands people crossing the border every day. With prevalence in the rest of the Europe often much higher than 1 in 10k, this means you always have a stream of imports.
Note that some of the borders look like this:
https://polar.cz/data/gallery/modules/polar/news/articles/vi...
you have a town on both sides, and in normal times, due to Schengen, people are used to work and shop cross-border. ?In such contexts you can prevent most of cross-border travel, but not all of it.
Here is one short analysis from the country simulated in the game, that is Czechia.
One of the regions got an alpha variant wave sooner and the local hospitals actually went over capacity, with triage going on. You can see it in the time-variable CFR plots.
[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).
I doubt this - it is impossible to kill 10% of the population in the game. As anyone can see on the final screen, max number of deaths in the game is about 150000, which is 1.5% (Czechia population is approximately 10M)
