Historically, it may not have been that desperate a siege as Sienkiewicz portrayed it and resistance against the Swedes would likely have occurred even without the siege but it did give a substantial morale boost.
I'll be using a modified version of Howard Whitehouse's Science vs. Pluck colonial role-playing rules. I've previously run games set in this era using some modifications for 17th century warfare (the rules portray late 19th century colonial warfare) - I call the modification Zagloba vs. Pluck. All of the players will be commanders in the Swedish forces, each with different goals that will be only marginally related to the successful capture of the monastery while I will run the Polish forces. The players will determine how to tackle the fortress, either by direct assault, prolonged siege, or even negotiation. Although only the small garrison was involved historically, I will include some outside forces attempting to aid the fortress, just to keep the players off-balance.
An escalade in progress
A raid on the Swedish lines by peasant rebels. This is one of the non-historical complications I've added to the game.
The Swedish siege lines
Here's some of the attacking forces:
Some Polish cavalry that had defected to the Swedes. Winged hussars, hoping to protect the holy site from desecration. Although there were some large bodies of Polish cavalry aiding the Swedes in the siege, there were no winged hussars but they are just so iconic of this era that I had to include them.
Kuklinowski's brigands, hoping to share the plunder.
A Scottish regiment under Colonel McFiltheigh
Swedish regiment, some of the finest troops in Europe
Some of the Polish forces. Prior Kordecki, leader of the defenders
A heavy battery