Cave Story started out as a free PC as I've mentioned earlier and earlier this year it was released on the WiiWare service. While being a pretty faithful port somethings were changed and I think for the worse.
The only change that I don't think was that big of a screw up were the graphic changes. The game has a softer look to it now with some of the hard lines smoothed out and more detail added to some of the character models. Here's a side by side comparison of Curly Brace.
The one of the left is the original PC release with the WiiWare version on the right. I really think the graphics are an improvement but something that maybe didn't need to be changed.
Next up they remixed all the music. The option to still have the original music is there and you absolutely need to use it. The remixed music is garbage and most of it is unrecognizable. I was really psyched to hear my favorite song from the Egg Corridor remixed and I couldn't even tell if it was the right song or not. It's a shame they would even attempt to screw with the already wonderful music this game has but they did and it is a complete failure. I would post a video of the new music but I don't think anyone should have to listen to that garbage. Use the original and you'll be fine.
The other big thing they changed was with Balrog. In the PC version whenever Balrog enters he yells out "Huzzah!" It's original it's neat not a phrase you hear often nowadays I really liked it. In the WiiWare version he says "Oh Yeah!" You know like Kool-Aid does when he breaks through a wall. It's not funny or clever or witty it's stupid. Anyone who is into Cave Story, take any person and if you say "Huzzah!" to them, BOOM they instantly think of Balrog. This is one of the main reasons and it may sound like nitpicking but I would never recommend the Wii version over the PC download.
Don't get me wrong Pixel deserves to make money from this amazing game but I'm just not a fan of all the changes they did in this when it came out on WiiWare.
There was an announced PSP version that was suppose to come out in 2007 but from what I've read it's dead in the water and that's fine by me because Pixel wasn't even involved in the making of it. If dude isn't going to get paid he at least needs to be credited for his creation.