I'll have to admit that I haven't finished it yet, and I'm not sure if I'll be able to muster up the strength to do so. I absolutely love the original game to tears, but the force tower defense sections in this game really sap all of the fun out of it for me. Really, any game that allows you to play for 15 minutes or more and then puts you in a fail state where you have to reload from that far back is the kind of thing I typically try to avoid anyway. So many times I've died in this game (always the tower defense, never anything else) and have had to restart these sections over and over again. It might be more fun if the game had like... predefined paths for the enemies, but it doesn't. You get a limited number of towers to place, and if you don't have them in the right spot the enemies will just completely bypass them. There is no way of knowing which route the enemies will take, so a lot of it feels like trial and error. There are tower defense games I love, but this is not one of those. In fact, it takes away so much that I almost get irrationally angry even thinking about it because it shits up one of my favorite SNES games.
The story is also WAAAAY too drawn out. It's cool having the additional narrative, as well as reasons for having "heroes" in the tower defense sections, but there are several times I feel like it just goes on a bit too much. Voice acting would help here tremendously. They've also removed a lot of the original game's freedom - you can no longer just fly where you want and do the towns in any sort of order, you have to do them all in a pre-defined way.
The side scrolling combat sections are definitely more floaty than the original. I play the original pretty often and the controls are TIGHT. This doesn't bother me so much, but it's definitely a huge departure from what was.
The music is amazing though, no denying that.
Thanks for listening to my TED Talk.