The landings were a complete surprise to the Polish–Lithuanian Commonwealth's defences, and despite his relatively small forces, Gustavus Adolphus quickly captured 16 Prussian towns, almost without a fight (with the neutral Duchy of Prussia's passive support).

The Polish hetman (historical army rank equivalent to field marshal) Stanisław Koniecpolski quickly came to his king's aid with a force of 4,200 light cavalry, 1,000 dragoons, and 1,000 infantry.

Engaging in a war of maneuver - small mobile units striking at the enemy's lines of communication - Hetman Koniecpolski managed to halt any further Swedish advances, even forcing the Swedes onto the defensive.

During the night of May 22 to 23, King Gustavus Adolphus was lightly wounded while attempting a night-crossing of the River Vistula in a boat near (Kieżmark), south of Danzig (Gdańsk), and had to retreat.

When, King Gustavus Adolphus was shot in the shoulder by a Polish sniper, the Swedes decided to end the assault and withdrew from the field, reportedly in good order.

Hetman Koniecpolski counterattacked by using his small forces most efficiently — fast cavalry melee attacks combined with the supporting fire of infantry and artillery, and using fortifications and terrain advantage.

Hearing of the defeat, the Polish Sejm was persuaded to increase funds for the army and accepted military aid from the Holy Roman Empire in the form of a corps of imperial troops under Field Marshal Hans Georg von Arnim-Boitzenburg.

Nonetheless, Koniecpolski was forced to withdraw from several strategic strongholds in Polish Prussia: in time he managed to recapture the seaport of Putzig (now Puck).

The Swedish king returned to Polish Prussia with substantial reinforcements in May, and marched south towards Graudenz (Grudziądz) hoping to cut-off Arnim's newly arrived imperial corps before it could join Koniecpolski.

In this encounter, while attempting to cover the withdrawal of his infantry, Swedish cavalry were subjected to a series of fierce engagements at the villages of Honigfeldt, Straszewo and Pułkowice.

With the aid of Arnim's heavy cuirassiers the Poles with their faster 'winged' hussars and cossack mercenaries were able to gain a great advantage over the light Swedish horsemen.

The war in Prussia demonstrated that the armies of the Commonwealth were poorly prepared for warfare requiring the continuous use or fighting of field fortification elements.

To a large extent, this neglect was due to the nature of the wars conducted by the Commonwealth in the eastern borderlands in the last century, characterised by the poor quality of fortifications, where the main importance in the vast spaces was given to moving cavalry rather than infantry and artillery.

The state, which had been at war on many fronts for a long time, showed serious financial shortcomings, which were greatly exacerbated by the blockade of Polish ports by the Swedish navy.

Gustavus Adolphus was also keen to end the fighting in Prussia, as he was in a hurry to join the battles being fought in Germany and assist the Protestant camp, which was experiencing serious difficulties following the defeat of King Christian IV of Denmark at Wallachia.

In addition to the financial difficulties of the state, the envoys of the Polish-Lithuanian Commonwealth were also prompted to the truce by the worrying actions of Moscow, which had established contacts with Turkey and purchased a very large amount of modern armaments, especially muskets, in Western Europe.

Meanwhile, Sweden, three years after the death of Gustavus Adolphus and with the terrible defeat at Nördlingen fresh in its memory, was at a crisis point and ready to avoid another conflict at all costs.

The new ruler of the Polish-Lithuanian Commonwealth, buoyed up by his impressive victory over the Russian army at Smolensk, wanted to consolidate his military fame, so he did not wish for any agreement at all.

Finally, on 12 September 1635, King Wladysław IV Vasa was forced to conclude another truce with Sweden in Sztumska Wieś, this time for a period of 26 years.