I actually played AKIMW BEFORE I played SMB, because the Master System came out first here in Brazil and, as you already know, was VERY popular here. Alex Kidd was as "iconic" as Mario here for a long time.
Still, I never liked it that much - and loved SMB when I first played it. It's not something I can explain, I guess; I think SMB is more...direct. Simpler, but not in a bad way. I get more fun out of it.