^^
Yes both were later - if I remember correctly - released on the NES, but the NES version of Shinobi sucked a** and was in general so shitty that no one wanted to play it even if they got payed to do so. Double Dragon was never released in Sweden because of Bergsala (basically Nintendo of Sweden) had a policy against violent games.
To continue the story about the Great Video Game War of the Eighties (in Sweden) from now on called tGVGWotE(S), there were lots of argumentation between the two camps, the NESers and the SMSers, sometimes even fights.
The arguments were pretty much the same as the ones you find on this forum between XB360 and the PS3. The Proponents of the NES said that the lack of AAA games on the SMS made it the worse choise, mainly the games LoZ and SMB. The defenders of SMS pointed at games like Golvellius and Alex Kid, which they said was far better both in graphics and gameplay. Another argument was that the NES lacked RPGs, something that was true, I dont think that a single RPG were released to the NES in Sweden. Another argument, probably the most common was "the argument on the lack of cool games", "all the war games and cool fighting games are on the SMS".
Well, we all know who "won" ;) Its not Golvellius or Alex Kid that people think of when someone mentions Video games :)