Its easy, up there, go to options, then select "advanced mode".
Now is just select a shape, go to "apearance" there will "Box Text:", then write the text there
10/10.
I'd like if you add jet packs and rocket launcher
http://www.algodoo.com/algobox/details.php?id=40312
this link has an robot(algodoo version) with a nice jet pack effect, you coud try to that effect for your robot...
Good luck