Well Spider-tsuman is only like $5, assuming you can get in and out without the little one picking up $200 worth of random Frozen mechanize. Much cheaper than a Roomba either way.
Unfortunately they don't let you move the space stations.
On the plus side though they equipped them with weapons that knock the giant spaceships around like bowling pins; so there's still plenty of potential amusement to be had. Edited, Mar 22nd 2016 12:09pm by someproteinguy
That monster in the mirror, he just might be you. -Grover