It was like that for me too Polaris. My first time involved wandering and eventually getting lost in the dark, deep earth! I had little clue of how to play, so it was just kind of weird... Fast-forward to much later, I ended up playing again and got addicted. There's SO much to find. And if you have a pal to discover it with, it's that much more fun <img src='http://www.cavestory.org/forums/public/style_emoticons/default/smile2.gif' class='bbc_emoticon' alt=':)' />
I played on my own too though, spent a lot of time building... Never did finish the floating island and tower...
@Gunblade - from someone who never played Minecraft, I think Terraria must have a lot more storyish-based content. There's even a Quote hat!
It's actually very different from minecraft. Minecraft isn't about fighting; it's mostly about building things. Surviving gets easy after the first two nights. Terraria, on the other hand, is all about fighting bosses and getting better weapons. It has 25+ bosses and hundreds of blasters, guns, swords, spears, drills, pickaxes, bows, repeaters.... It's also a lot harder-- In Minecraft, diamond armor pretty much makes you invincible (unless you're in the end, of course), but in Terraria, most bosses and enemies stay hard far into the game.
Not to mention there's Hard-mode, which early on without proper equipment will rip you to shreds. (R.I.P hardcore CCL; died to the first boss in hard mode)