I've never played the game before, but this part has got me interested. Like Zelda II? I must investigate...
Don't take that to mean they're very close, at all. There's no free-roaming overhead map and thus, none of Zelda II's semi-random overhead battle encounters, no magic (at least, that I can see so far!)... it's just the first game comparison I thought of, since both feature a sword (that shoots) and side-scrolling platforming. You can also increase your HP, upgrade your sword (oops, I guess I mentioned both of those already), and shop and talk to townsfolk. The overall vibe, thus far, just kinda reminds me of Zelda II. But on its own, it's still a really fun game so far.
I guess it's actually closer to a Wonder Boy game. It's cheap -- pick it up when you can.