Today's robot is SPIK3R, which is provided by Lego. Unlike TRACK3R, the instructions are only available in the software that you can download on the Lego site, and that is the same where you program the robots!
This one is definitely a more complex robot than TRACK3R, both for those who are building and for those who only see once built! What I found most "difficult" was to assemble the legs, it has an interesting mechanism for this to move forward, backward, and still feel that are these that make it walk! (all this is visible in the video below) Despite that, Lego continues with the good work of making clear and simple instructions, which made this part the best and where I learned more assembling techniques to apply in my constructions!