You may exit to the map after the boss chest is opened.I added some optional filler levels to the commonly suggested list (they’re the ones not in bold style), they are not required for skipping levels: This is the list of the checkpoint levels you need to beat, in order to skip levels successfully. The ordered list of required levels is shown in the next section. It should be noted that you need to beat the checkpointlevels in the “campaign” order, that is the same order they are unlocked by playing normally. If you do this the correct way, you can even get the silver/gold skull and unlock the extra characters at the end of the campaign, but we’ll cover this in another section. In such a case, you just have to play (and beat) all the checkpointlevels on the map, then all the levels will be unlocked for the solo campaign of every player in the party. In other words, if one character in the party has already unlocked all the campaign levels, they will be available for the whole party. When you play the campaign with other players in coop, the campaign progress corresponds to the most “advanced” one between the players’ characters. For example, if you beat the checkpoint level Barbarian Boss then you beat the checkpoint level Thieves’ Forest, the intermediate filler level Forest Entrance will become permanently available and you can access it even if you exit the game session and start a new one. Here comes the trick: when you complete two subsequent checkpointlevels, the intermediate fillerlevels between them are registered as “beaten” even if you didn’t actually play them. When it happens, the game also registers all the intermediate filler levels as “beaten” and all these levels are unlocked on the map. As I said in the previous section, the game saves the campaign progress when you beat a checkpointlevel. Now, let’s talk about how level skipping works. Please note that character progress is always saved as soon as it occurs (ex. For example, Barbarian War is a filler level: as soon as you beat it, Barbarian Boss becomes available on the map however, if you exit the game session at this point and start a new one, Barbarian Boss will be locked and you have to beat Barbarian War again before proceeding. Therefore, if you exit the game session and start a new one, you cannot immediately play the latest level unlocked but you have to unlock it again, playing the previous level(s). On the contrary, when you complete a fillerlevel, the next level is unlocked but the game does not save the campaign progress. I suggest you read the whole guide from the start, but there’s a Summing things up section with the essential points for the TL DR guys. I wrote the guide using a verbose style because I wanted to be as clear as possible. I had such problems myself, so I decided to make this guide for all the players who are having a hard time with level skipping and had no luck with the other guides. The result is that many players end up having issues: the campaign levels stay locked, the player does not get the silver/gold skull, the extra characters are missing. However, they’re not always consistent and there are a few differences between the guides themselves. There are a lot of good guides for level skipping out there. This procedure is known as level skipping and makes it possible to beat the game faster, also getting the silver/gold skull and unlocking the extra characters (when done right).
Maybe you have heard this workaround somewhere on the web, many players already know it: it is possible to beat the Castle Crashers campaign mode skipping some of the regular levels. You tried to skip campaign levels but it didn’t work, or you skipped the levels with success but got no skull/character after beating the game.