What can the Duck Hunt Dog do?
First off, he is a hunting dog... and what does a hunting dog do? There are several things hunting dogs were trained to do... they locate game and point them out for the hunter... they flush game out of its hiding place when the hunter commands them to... they retrieve shot game to the hunter.
Now, what did the Duck Hunt Dog do in the classic NES shoot'em up? See for yourself...
He smelled the ground and located the ducks... he jumped in the grass to flush them out... he retrieved the ducks. He is based on several types of gun dogs such as retrievers, setters, and spaniels.
I see that the movesets for Rosalina & Luma and Little Mac involve something unique to make them stand out... Rosalina with summoning Lumas and using gravity effects... Little Mac with building up the meter before he can one-hit KO opponents. Well, I do think that the Duck Hunt Dog has something that can help him stand out...
Watch the video again... see that? The hunter shoots the ducks! That one is gonna be the neutral B move... he does his hunting dog duties like pointing the prey (the opponents) for the hunter to shoot... he flushes ducks out so the hunter can shoot them down... how does that even work, you might ask. Well, when you press the B button, tall grass inexplicably grows quickly behind the Duck Hunt Dog and he jumps in the grass... then he flushes out a duck... from there on, you assume control of the flying duck with the control stick (or circle pad on 3DS)... this one is based on how you would control ducks if you plugged the NES controller in the 2P slot... watch the video...
Now that you got the idea (hopefully)... while you are controlling the duck with the control stick (or circle pad on 3DS), you have five seconds to fly the duck to the opponent before the duck flies away and the Duck Hunt Dog comes out of the grass, laughing at you, and you assume control of the Duck Hunt Dog again as the grass disappears in a poof of smoke... so, when you are controlling the duck, you must get it close to the opponent before you press the B button again for the hunter to shoot at the duck... the opponent would be harmed by gunfire explosion... see the gunfire explosion on the Duck Hunt NES cover?
Of course it won't be pixelated but you get the idea... when the duck is shot, it falls straight down like in the NES game... now, if you managed to get the duck to overlap with the opponent's body and timed your shot, well, it would be an one-hit KO, especially at high damage percentages. If the duck overlaps with the opponent's head, it would be a headshot and results in a Meteor Smash and the opponent drops like a duck.
Wait, there's more... watch this video...
The hunter shoots the clay pigeons (frisbees) too. This one is gonna be the Side+B move. How would this one work? Well, the Duck Hunt Dog could pull one out of hammerspace and throws it. The controls are very similar to Link's boomerang throw... except you need to press the B button again after throwing the clay pigeon for the hunter to shoot the clay pigeon. So, even if the clay pigeon hits the opponent, that opponent gets minimal damage with no knockback... just like Fox's neutral B move... but if you press the B button when that clay pigeon is very close to the opponent, the hunter shoots at the clay pigeon, it explodes into shrapnel and and the opponent gets major damage and gets knocked back... so if you time your shot, you could potentially score an one-hit KO when the opponent already has a high damage percentage.
The Duck Hunt Dog sounds potentially overpowered with one-hit KO projectiles... good thing there is a game mechanic that prevents players from spamming neutral B and Side+B moves... see the ammo in the bottom left side in both videos? The hunter can only have three bullets per round in the NES game... but in Smash, after using up three bullets, the hunter takes ten seconds to reload the NES Zapper... so the Duck Hunt Dog player needs to be conservative with the ammo (at least when it comes to special moves).
One of the most-remembered things about the Duck Hunt Dog is his trolling laughter. Many gamers of the 1980's wanted to shoot that dog for laughing at their failures... so the Duck Hunt Dog's Down+B move is going to be about that. When the player inputs Down+B, the Duck Hunt Dog looks at the screen and laughs at the hunter... only to be shot at. This deals 20% damage to the Duck Hunt Dog... however, if the Duck Hunt Dog's body is overlapping with the opponent's body... well, it is gonna be like Jigglypuff's Rest move... with the hunter shooting at the opponent instead of the Duck Hunt Dog. If this was done to the opponent when the damage percentage is high, well, it is another one-hit KO move. Again, I stress that this move should not be spammed because you are shooting at the Duck Hunt Dog... therefore, the player cannot afford to miss the opponent and accidently one-hit KO the Duck Hunt Dog.
So, with the emphasis of one-hit KO projectiles and limited ammo, the Duck Hunt Dog is about shooting with precise timing and diligent patience... just like real life hunting... except the hunter is using the NES Zapper the whole time!
As for the Up+B recovery, the Duck Hunt Dog pulls out two ducks from hammerspace and starts flying around. He flies faster and farther with two ducks than he would with one duck... the controls are like Pit's Up+B recovery.
For the Duck Hunt Dog's normal moves, well, he could just pull out ducks from hammerspace and use them as bludgeoning and throwing weapons. After hitting the opponent, the duck flies away... and it pecks opponents on its way out. His aerial down+A move could have the Duck Hunt Dog throwing a duck straight down... and it is spiraling on its way down, like a drill...
Remember that one of the hunting dog duties is pointing at game so the hunter can see where the hunting dog is pointing at and shoot there... since the Duck Hunt Dog is a cartoon dog, he could point fingers at different directions, telling the hunter where to shoot at... so when the Duck Hunt Dog points fingers at the opponent, the hunter shoots at the space just beyond the Duck Hunt Dog's fingertips... these moves don't use up ammo like the special moves and they don't one-hit KO opponents either.
So... basically, the Duck Hunt Dog fights by constantly breaking the fourth wall by having the person playing Duck Hunt (the hunter) do all the shooting with the NES Zapper. This is highlighted in the Duck Hunt Dog's Final Smash where he jumps in the grass as dozens of ducks fly out of the grass... and the NES Zapper appears in front of the stage, complete with a crosshair. You control the crosshair and you can press the B button to shoot. You get three bullets but each bullet is a guaranteed KO regardless of damage percentage... but you need to aim carefully to shoot at the opponents and not at the ducks. It would be like this...
In my opinion, I think the Duck Hunt Dog is probably suited for advanced players who appreciate the challenge of precise timing and diligent patience because scoring an one-hit KO successfully can be very satisfying... and of course for beginner players who are too scared to get close so they just camp. It is fitting as "camping" originally came from the first-person shooter game genre... and Duck Hunt is a first-person shooter game.