To be fair, Simon did get another re-design during the Lords of Shadow games:
Though I'm not sure if that's really any better. Of course, the overall "problem" with Simon as an amiibo is that the Castlevania games rarely feature the same protagonist in each installment. Simon is just one of many Belmonts, and other than old-school Nintendo nostalgia, why choose him over Richter? Or Trevor? Or Christopher? Heck, it's arguable that Simon isn't even the most popular Castlevania character - many would say that Alucard is favored far more.
Maybe Dracula himself as an amiibo would work better to represent the classic Konami franchise.
Earthworm Jim was pretty cool. His games are available on DSiWare, XboxLive, PSN, and Wii Virtual Console. I seem to recall the original was brutal. Very challenging. But it's been a while since I've played it, so my memory may be foggy.
It's only a few bucks to download, so I recommend checking it out. If only for nothing more than a history lesson, or to satisfy curiosity.