During the summer FRC 6328 runs an FLL summer session for 10-13 year olds, and last summer we started developing a custom FLL game based on the current FRC game. The game is designed to be simple enough so the students can build robots to complete the missions either in a 5 day long camp program or during once a week meetings for 5-6 weeks (that is what we do on 6328). It is also a good way to get FLL kids interested in FRC since they get to play a LEGO version of the FRC game!
We just finished designing and making the materials for FLL Destination Deep Space, and you can access the game manual and mission model instructions here:
If you want to check out FLL PowerUP those files are here:
We usually mix in fun core values challenges to the meetings, as well as mini projects that are related to the upcoming FLL game. For example, during the summer before the Hydrodynamics season, we did a water filter design project as well as coagulation/flocculation/sedimentation experiments to learn about drinking water treatment. Those were a ton of fun and a good way to break up the sessions.
For the younger kids (5-9) the WeDo 2.0 kits can be a ton of fun. When we work with younger kids at demos we always bring one of those kits. They are not too expensive and always a hit!
Good luck with planning your camp!