While the original StarTropics was a great game, it did have some nagging problems. In 1994, after the SNES was already out for 3 years in the US, Nintendo saw fit to finally make a sequel to one of the (sadly) most underrated games on the NES. But they didn't make it for the SNES - They actually made it for the NES as well!
In Zoda's Revenge: StarTropics II, you once again assume the role of Mike Jones. He's back in Seattle with his uncle after his tropical adventure, but then he's suddenly telepathically contacted by one of the children he rescued at the end of the original - She tells him that Zoda is still alive, and he's now attempting to collect the powerful Tetrad blocks, which are scattered through time. With the help of his uncle and an ancient book, Mike travels through time to get every block before Zoda does.
It's a bit of a cliche'd plot, but it works - It does of course mean that you'll visit lots of vastly different locations. You first appear in an ice age, but you'll also travel to ancient Egypt, 19th century London, and even C-Island from the first StarTropics!
The general gameplay is the same - First you do a bit of investigation on the overworld of an area to find out where to go and maybe get some items, then you go into a dungeon to beat the bad guys. Most chapters have 2 dungeons each this time. While the overworld sections aren't really different from the original game, the dungeon sections are vastly improved - Instead of only being able to move up, down left and right, Mike can now move diagonally as well. This obviously makes it much easier to navigate - He also doesn't have to temporarily stop in order to change the direction he moves in, so you can avoid danger quickly.
Another change is that you can now jump at any time while in dungeons - Of course this includes diagonally, so you'll find that it's much easier to navigate platforming sections. To take advantage of the fact you can now jump at any time, there are also moving platforms, and even higher floors in rooms - For example, you might have to jump up a stack of crates!
There's one more change - In the original, you could use stronger weapons by having more health left, which basically meant you had to try and keep your health full the whole time. Not this time though, as you will lose your previous weapon when you get a better one, meaning you can use your strongest weapon at any amount of remaining health. The "degrading weapon" feature has been turned into a secondary magic attack - This attack is weaker than your main weapon but travels further. Once you've found an upgrade for it, having lower health will cause your attack to become weaker.
Graphically the game is not much to speak of - It's pretty much on the same level as the first game. The soundtrack varies wildly though - Some of the dungeon themes are amazing, while most overworld themes are quite dull. Overall it's quite good, as it has tons more variety than the original, but the overall quality is a bit lacking.
StarTropics II is a great game - But while it fixes problems from the original, it introduces new ones! One of the biggest ones is the addition of pitfalls - On a few of the overworlds, you will occassionally stumble into invisible pits (They are in set locations, not random) and land in a mini-dungeon you have to fight your way out of. In fact, the game even begins with a few of these! Overall, the game is still very enjoyable and worth your money, but it doesn't beat the original.
It's really a shame Nintendo decided to release the game for the NES, if they had released it for the SNES, perhaps the series could've still been going today. The game was released in the US so late that there was no more time for a PAL conversion, this means that if it's released on the European Virtual Console, it'll most likely cost 100 Wii Points extra as it'll be an import.