Hiya chaps, I'm the one behind this particular Kickstarter, nice to see it under discussion!
The Mule is a tricky one, it is definately not Steampunk as it stands, however it did slot into the Kickstarter as its potentially useful for the guns use with non-steampunk gaming systems. We are planning a more Steampunk version of it in the future, but thats on hold for the time being.
If you've not been back to the campaign page though, you may be interested in some of the updated images of the weapons which are unlocked, though I will mention the campaign ends tomorrow if you are interested at all.
The finished weapons include the Autocannon and Gatling Cannon, I'll post some updated, but not finished, pictures of the Tesla Cannon on the campaign page tonight as well.


You might also find this video of how the Autocannon is 'intended' to operate as well.