I'm going to take a little different route regarding this game. Mostly I'm going to do a contrast and compare with the PSP version. They certainly both have their strengths and weaknesses, but lets see what makes this version of the game unique and why it was worth playing along side the PSP version in my only repeat game of the entire thesis.
The story of Final Fantasy IV DS of course is identical to the PSP Version, however is told in a slightly different manner. That is of course, because the DS version introduces voice acting in the cut scenes. Now, these are not the greatest voice acted scenes in Final Fantasy history... but they are not the worst either. Obviously, the producers know that one of the high points of this game and the one that makes it stand out the most is the story, so adding this to emphasize it is certainly a bonus. I just wish we could've added a line where Cid says that something's power is over 9000... that's all.
Next, let's talk about the graphics. In PSP we have an updated version of the original. Basically, a sharper more refined version of the sprite graphics. The DS version uses a 3D engine. That's right, we have what seems to be an updated and more importantly upgraded version of the engine used in Final Fantasy III on the DS/PSP. They did a very good job of recreating everything without making changes to simplify maps or dungeons. Some of the general feel of the dungeons was changed. Most notably the towers were made a little less futuristic looking and the Sealed Cave was given a more volcanic look. Unfortunately, the mini-maps they added are usually the focal point of your movement through the dungeon, so some of the graphical upgrades are not fully appreciated. Another note is that the engine can handle more objects in battle over the FF III version of the engine. So, some of the more memorable encounters are preserved... with one standout. Yeah the Bog witch + 6 toad encounter... now only has 5 toads... not a big deal, but I noticed it.
The battle system... well, first off, lets start with the difficulty. The difficulty of the DS version has been ramped up CONSIDERABLY. Mostly because monsters will damage you alot more than they ever did in any other version I can think of. Also, most of the boss encounters have been changed to actually include some strategy to them. Most have some kind of counter or timing element to them. Your abilities have changed somewhat to. The game includes what are called Augments. These serve 2 purposes, one to either upgrade or give you new abilities to use in battle. Also, at high levels they are the sole influence of what stats you gain on level up. On your first playthrough of the game, you can ignore alot of the stat upgrade ones... you'll find the useful ones in battle pretty much immediately. Draw Attacks gives you the option of making a tank character in the game... something that is definitely different from other versions. Omnicasting makes it easy to buff your party, etc. Also, you can get back some of the abilities of the characters that leave your party allowing them to live on so to speak.
The postgame content... well, in the PSP version we had the Lunar Ruins in the main game as well as a full version of the After Years. In this, we have a few crazy things going on. First of all, you have the option of going through the game 3 times. This is to give different people different augments and max stats, etc. Each time you finish the game you also get a Limit Break augment allowing a character to deal up to 100k damage in an attack. This is to deal with the Super Bosses which I will get to shortly. If you want to take out the super bosses, you are also going to need to farm rare items. Completing every mini-map in the game gives you the Treasure Hunter augment which doubles the rare drop rate of items. This is useful because if you want to take down Geryon and Proto-Babil you are going to have to spend hours farming... First off are the Pink Tails which give you Adamant Armor. 5 of these are almost required. They also make it rather amusing when going back through the game. Red Tails for Onion Swords are also nice... these swords grow in power as you gain level. Other ones for gaining speed and other stats are also available but less needed since you can max out your stats anyway with the Augment system.
The game includes 2 super bosses which can only be played on a 2nd or 3rd playthrough. The first is Geryon, and I believe he was made to kill on your 2nd playthrough. He has all the abilities of the Elemental Archfiends and he hits like a truck. Really though, he's not very hard.. especially if you have Adamant Armors... and know how to cast Blink. The point of him I think is that he gives you 100k gold and a lot of experience, allowing you to level up quickly and afford items like Sirens, Elixirs, and Shurikens. The other super boss is Proto-Babil. To access him you need to first steal Dark Matter from Zeromus and use it on the entrance to the Lunar Ruins... or at least where it is in the PSP version. He is meant to be killed on your 3rd playthrough when you have access to 2 Limit Breaks... I killed him with only 1... He is immensely difficult, needing a dedicated tank and healer and a lot of damage.. and that's just phase 1! His first phase includes an attack that will deal 10k damage unless you defend or brace, and an instant death attack which is nullified with Adamant Armor. He will also sometimes counter for 4k damage on everyone. After dealing 280k damage to him, he becomes a beast, he speeds up, and either heals for 28k or does a 7k+ attack to everyone. And his counter changes to instant death on one party member that can't be blocked... So, while the fight has a learning curve... really the fight is pretty easy if you can force a lot of damage through quickly and avoid phase 2 by doing 120k damage before he gets an attack off. Doing it with only 1 limit break... on a character who couldn't do 99999 damage though... was rather difficult, and on par with Iron Giant I'd say.
Another note on the Augments. Being able to get multiple copies allows you to do some interesting things. One I'd like to point out is the Twincast augment. Yes, this basically useless ability from the main game has some interesting uses. By giving it to the Final Five, you unlock some interesting combinations. You gain access to the buffs first introduced in FF XII. Bubble (2x hp), Bravery(Atk up), and Faith(Mag up). Also, Cecil and Rosa can dualcast Ultima, the best magic spell in the game. Also, what you Twincast is not random... it uses a Sync property where you need to keep the two characters HP and MP within 20% of each other (based on their Max HP/MP), to get the desired effect.
So, would I rather have the PSP or the DS version... Based on the full versions, I'd lean towards the PSP version. The After Years is a great game by itself, and I've always found the Lunar Ruins to be a very enjoyable dungeon with some fun items, and being able to switch to some of the older characters is a fun addition. Going solely on just the main game, however, I'd lean towards the DS version. The challenge and engine are a step up, even without a Fast-forward button, and you get a much better sense of accomplishment finishing the game I think. In conclusion, both versions certainly have their pros and cons, but really its Final Fantasy IV... you can't go wrong with either one. I still consider this game to be the baseline of any JRPG. Such a great story, with simple easy to learn mechanics. I think this game should be the starting point for people who want to play JRPGs for many years to come.