Embedded Security CTF
 

a little hacking game related to RE
https://microcorruption.com/

here is simmulator which you can use for offline solving: https://github.com/cemeyer/msp430-emu-uctf
and there are solutions in case you are lost in code :D
http://ponies.io/posts/2014-09-16-microcorruption.html

enjoy :)