Pretty cool demo. I like going for the legs most of all, maybe that's why real world tanks don't have them. I think the Orion is a good middle ground to expand from to create all sorts of different builds and configurations, although I'm not sure how you can encourage people to do this.
On a different note, an issue I had which I want to point out was that using the automatic weapons overheats my mech instantly whereas auto-lasers and single shot weapons work fine.