B - War Horn - Like Falcon Punch, a really powerful move with a long startup. Unlike Falcon Punch, it's an area of effect attack that hits all around.
Up B - Throwing Anchor - He throws an anchor in an arc.
Down B - Phase Locket - Shovel Knight becomes invulnerable for three seconds. Takes about a minute to recharge after you use it.
Side B - Mobile Gear - A projectile that rides along the ground. If you hold B, Shovel Knight will hop on. If you're in the air, this means you get your jump and double jump back - but it can only be done once in the air, of course.
A - A basic thrust of the shovel.
AAA - Repeated thrusts with the shovel.
Running A - Shovel Knight thrusts his shovel into the ground and plows through the opponent. This attack hits multiple times.
Forward Tilt - Shovel Knight slashes his shovel like his charge attack.
Down Tilt - Shovel Knight smacks his shovel against the ground, causing a spark.
Up Tilt - Shovel Knight thrusts his shovel upwards, like in his victory pose.
Forward Smash - Shovel Knight digs up a gem. The longer you charge, the bigger the gem, the more damage it does.
Down Smash - Basically Villager's down Smash. He digs left and right and buries opponents in the ground.
Up Smash - Shovel Knight twirls his shovel above him, hitting multiple times.
Neutral Air - A basic thrust, much like his standing A.
Forward Air - An overhead swing with both hands. Spikes.
Down Air - Shovel drop. Works much like Link's down thrust.
Up Air - An upwards thrust.
Back Air - Shovel Knight spins around and swings his shovel behind him.
I've spent too much time thinking about this. It just makes me sad that it won't happen.