For Those who don't know what is Shooting Watch,
Shooting watch originally created by Hudson, since Tri and other ppl love how Meijin can Push button 16 Times in 1 Seconds with a game watch called Shooting Watch, many ppl try to break the record by using the machine, unfortunately the Shooting Watch is super rare, and already produced again since the 20th Anniversary of Shooting Watch, but in Limited Production (see Shooting Watch DS)
later Tri decided to create a homebrew based on this Gamewatch, with Retrohead Shooting Watch DS was born...

Since Shooting Watch is small game, I think Hudson never created the game via Cart... instead after DSi born with DSiWare, Hudson decided to put this on DSiShop, not a copy of Tri Homebrew at all...