MDBT42 + breakout

Having made a cardboard cube to find out if the size feels right, one could also consider what to do with the boring base, add wheels and some light sensor(s) and http://ozobot.com/ as an add-on "when/if the time is right" either by oneself or by peripheral suppliers to a proven espruino sw base.

Make sure the cube has some means to be pinned into for some form of bigger bot so the kids have something a bit bigger at some time
I mean, this is just plain ugly
https://www.kitronik.co.uk/wp/wp-content/uploads/2016/02/bbc_microbit_line_following_buggy_top_870.jpg

Even after a bit of presentation work, there are still "big problems" and in the end, one says to one's self "there must be a better way"
https://github.com/microbit-drill/buggybit/blob/master/README.md

Edit:
What would make one version of a cube case, look at the espruino logo: the handle of the coffe cup could also have a function, what about a set of rgb's nicely down it?

Edit:
Or just a Big Red Button on the top of the handle and use the hollow of the cup for cool things like a couple of buttons and a 5x5 led display add on or what about a 5x5x5 RGB Led stack.
The hollow of the cup could also just be a place to put one's puck.js so one can find it again while making integrations between the cubebit.js and the puck.js
Put the cubebit.js on another add on, an induction charger where the internal coil supplies power to the rechargeable batteries as another add-on

Peripheral business with suppliers of well thought out add-ons who can also take some of the pain of assembly and test of possible DIY espurino kits