First of all, welcome to the PLC! Glad you are here and seeking for helps.
We don’t have a folder of solutions to the STEM Lab. But for castle crasher, you could take a look at this posted solution NEW IQ STEM Lab: Castle Crasher - #9 by Lauren_Harter
Please let us know if this helps. And we encourage you to keep posting your questions here! There will be other educators who will hop on and answer questions as well.