Like the title says, I would like to know which are differences in The Baconing's gameplay respect to previous chapters of DeathSpank.
There aren't that many gameplay differences, aside from balance changes like the availability of ranged weapons (compared to Deathspank 2) and more focus on combat over exploration and puzzle-solving. There's at least one entirely new feature, and another that feels new:
In this iteration, Deathspank has a shield which can be used to absorb damage and (if the block is perfectly executed) recharge your special power instantly. This does make the combat a bit more tactical, which might be a big deal considering how much more of it there is.
Some of the new Weapons of Justice have greater abilities than those in the last game, like calling in an airstrike (from a dragon, no less) or sending out subterranean spikes against your opponents.