Haha, this is like the fiftieth WI about Gustavus... Still, it's always interesting. Say Wallenstein doesn't inform Pappenheim in time because of faulty reconnaissance and Swedes win, Gustavus survives and the Catholic army is crushed. A lot of German mercenary captives would of course switch sides. Bavaria would end up ravaged and firmly under Swedish control with Bohemia in grave danger. IMO the Emperor would have to ask for peace within a year after a couple more smaller defeats. Then Gustavus could achieve his dream of becoming an Emperor but not the Holy Roman Emperor. He wanted to proclaim himself an Emperor of Sweden and Denmark above the Sound straits, as an Emperor to counter the HRE with a league of Protestant German states under his protection, primarily Brandenburg and Saxony. They would be nominally be loyal to the Swedish Emperor but would have almost complete independence, something maybe like the HRE in its final stages. I see the Swedes losing the Imperial title to the Prussians sometime in the early 1700s due to standard demographic reasons, though even Prussia as we know it might be butterflied away and Sweden could be stronger in the long run. Sweden would also get probably all of Pomerania as Brandenburg would be inferior and to weak to challenge Swedish claim. But they wouldn't get Bremen-Verden as it was OTL taken from the Danish prince in the war of 1643-1645. Thus, they get all of Pomerania. Plus Wismar.
Gustavus could possibly father one more child. If it's a son the Imperial succession is secured. If a daughter then Karl Gustav von Wittelsbach could be married to Cristina and be an Emperor while she is the Queen of Sweden in her own right. Though I'm not sure would she have kids, that second daughter of Gustavus could have future progeny with some powerful Protestant prince. If Gustav has no one else but Christina there is still a younger brother of Karl Gustav, named Adolf Johan who could have children. He would be the heir as his family were actually the closest Vasa relatives of Gustav and Cristina.
There would be a string of wars across Europe after TTL shorter TYW with France probably ending its support for Gustav but they could ally again if necessary. Or become greatest enemies, it depends on the situation. I guess the Danes and the Poles would quickly attack Sweden but it would be useful. They can use their position and power to crush them both and if a victory is strong enough, take Scania, Halland, Blekinge, Bohuslan and maybe Bornholm together with Jamtland and Herjedalen, Bremen and Verden in Denmark though it depends on small details such as who controlled it at them time though if its in 1640 its plausible, but I'm not sure about all of Norway... It might take another war...besides, if they want all these gains you need to have the Swedes allied with the Dutch. OTL the Dutch broke their alliance with the Danes because they raised the Sound tolls. Have the Danes join the war, start losing and then raise the tolls to get more money for the war effort. Then the Dutch ally with the Swedes and later Swedes can help them against France, something like the OTL Triple alliance with England. Oh and against Poland they would definitely take Courland (compensate the Duke Kettler with some money) and cities like Gdansk and other that control important rivers (Neva, Daugava, Wisla, Oder, Elbe and Weser-altogether a huge income).
The effect on colonies is also important. If set up properly, New Sweden could fare better than OTL. Especially with royal encouragement. Immigrants would not just be Swedes but also Finns, a few Estonians and Curonians, some Danes and Norwegians, couple English merchants and sailors, a decent number of Dutch, especially if they are allies and plenty of Germans, looking for new opportunities and fleeing from the war devastation at home. Oh and French Huguenots eventually. It could result in Swedes actually being not the most numerous nation in their own colony. Apart from New Sweden, they could sail into Hudson's bay if they are feeling adventureous and settle up there at the same time the English did. From there it's easy to move into Ontario and Manitoba and Swedes are no strangers to cold. From there the Great Lakes and OTL Minnesota are not far away and OTL a lot of Swedes moved to Minnesota IIRC. All that before 1700. And of course the Swedish Gold Coast (a beautiful name

) and couple islands in the Carribean who knows? But it would of course be less populated that the Dutch or English colonies...However it could also affect New Netherlands and Louisiana so the USA are probably butterflied.
Anyway, hope any of this helped and it wasn't too much. Thanks for reading all this
