Here are various shots of Kingdom Hearts: 358/2 Days during it's development, Square, for seemingly unknown reasons decided to release screenshots from all kinds of builds seemingly randomly up to it's release in Japan so it's hard to tell at what point of development these shots came from.

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Left: Prototype / Right: Final
Twilight Town: This screenshot shows us Roxas hanging from a ledge with a Shadow (heartless) over him. In the top corner there should be a counter which increments when you defeat heartless. Here however, it seems to show mission objective completion.
The HUD in the bottom corner is also vastly different to the final as well. Roxas' face is different and there are 3 bars, where as in the final there is only one. The green bar is the HP bar, blue bar is the MP bar and the yellow bar is the Limit bar.
The blue MP bar is not used in the final at all. While there is magic in the game, it's usage is not determined by MP. Instead, magic spells are instead equippable items which you add to your 'slot panels' (think of them as an inventory for everything), each slot for one magic spell means one usage, unless the slots are placed in multiplier squares, it's quite complicated but the bottom line is; no MP in the final.
The limit bar still does exist along with the mechanic in the final game, however, it's now integrated with the HP bar. The Limit Bar in the final over-lays the HP bar at the bottom of the bar, when the player's HP bar depletes to where the Limit Bar begins, the player can use the Limit bar to unleash powerful attacks which vary differently between characters.


All player icons down the right-hand side of the screen are different in the final. As the final HUD only has one bar to display for any character, there is only one bar displayed for all icons down the side of the screen, not two as shown here.


Same differences as the first and second images


This shows the Scan ability, which shows the enemy Heartless' HP in the top right-hand corner. However in the final the name of the Heartless you're fighting appears over the top of the enemy HP bar. Here it does not. There's also the text "Lock-on" under the HP bar. This text appears differently in the final and also appears centre-top of the screen, not far-right as shown here.


Top screen shows similar differences previously noted. The bottom screen is vastly different to the final. The "Information" pane shows the text scrolling along the top of the screen. In the final, all text is static and wraps into two lines, not just one. There appears to be arrows either side of the world icon/map middle-left and middle-right of the bottom screen which appear to be UI elements. However, their use is unknown as the final game has nothing like this.
The bottom of the screen is also interesting as well, in the final it shows the "Mission gauge" which is a progression bar which fills when certain critera are met or an event is triggered, here it refers to "Days" and "Mission Days" which is most likely referring to the two different types of gameplay the game has, with a story mode and mission mode. The "Days" mode is the story side of the game. The "1/1" most likely refers to how many missions are currently queued in the mission select menu, for important story events only 1 mission is on display, as is with the "Darkside" mission, which the text under "Days" mentions.


Here is a similar shot to the one above, however mentions "Hologram Mission" this is a gameplay mechanic which enables players to re-play old missions from days gone by. It may also refer to the Mission Mode.


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Different HUD, extra bars, etc


Different HUD and extra bars. This area actually depicts the forecourt to the Mansion inside Twilight Town. This area is never available to the player to enter, it seems that the gate to the forecourt is missing in this screenshot.


A near-er final shot of the game. Notice how the bottom screen no longer displays the arrow buttons either side of the map. The bottom screen does not show the Mission Gauge, however for this Mission, it should. There is also no Limit Bar on Roxas' health metre, Roxas' icon in the game is also different in the final. Xaldin's face icon also differs in the final.


Hard to see because of IGN's faggotry, but there's no limit bar over the HP bar and Roxas' face icon is different in the final.


No limit bar, Dyemix's icon is different in the final.


All icons here are different in the final, the "scan" ability is shown here again, there is a space above the enemy HP bar for the name, however is still not displayed here. No limit bar.


This shot actually shows the "Mission Gauge", however in subsequent images it's named "Mission Inside". The final game uses the "Mission Gauge" text. Xion's icon is very different in the final, as is Roxas'. No limit bar on HP bar.


"Mission inside" text. Usual HUD differences including missing Limit bar. The Scan ability, however, now does show the Heartless' name above the HP bar.


Icons different in the final. No limit bar.


Here's an interesting shot of the Panel Slot menu. There are a number of things different here. For starters, Roxas' face on the top screen, top-right is slightly different in the final. The green button, top screen bottom right should have a white circle in it which encompasses the "X" making it look like the DS face button X.
On the bottom screen, there are tabs above the Panel Slots themselves (labelled 1, 2, 3), while this does appear in the final, they only appear when your Panel Slots exceed the amount available on the screen. The green "Y" button does appear, however is smaller and rounded like the DS face button "Y" and hugs closer to the inventory rather than the tabs.
The Inventory tabs are different in the final. In between the green potion tab and the purple Magic tab, there should be a brown "attire" tab, however this is missing. The icon for "Valuables" has a different icon in the final and looks more like a basic diamond shape rather than a complex 3D drawing. There is also a "Recipe" tab to the far right, but in the final all recipes are kept in the valuables tab. The "L" and "R" buttons are more square in the final, not triangular as they are in this shot.
One oddity with this screenshot is that there is a cursor hand icon over the Panel Slot section of the bottom screen, yet there is a red selection highlight on the top screen which only appears in the final when you are actually selecting something on the top screen, however this also moves the hand-arrow cursor from the bottom screen to the top one.


Another shot of a later prototype. Roxas' face is still different, the text underneath his icon is wider than it is in the final. To the right of this at the bottom of the box, the bottom field of this box says "Trial Point" and measures hologram missions the player has cleared. In the final, this is re-named "Mission Record" and underneath this and missing in the above shot is the "rank" which is assigned to the player as they progress through the story mode and clear hologram missions. The Level Up description is also more informative in the final. It may be for demonstration purposes, but the player is only level 9 in the game, yet has all slots available, normal progression through story mode will not unlock all these slots for a player, let alone unlocking them all at such an early point in the game.


As with the previous shot, Roxas' face icon is different. The information field which is at the bottom left of the top screen does not have specific instructions on how to scroll through the top-screen information box, this information is present regardless of how far through the game the player is. The Blizzard information on the bottom of the bottom screen is different in the final.


Mission Inside instead of Mission Gauge, no Limit Bar.


Icons all different in the final, no Heartless name above Scan ability HP bar.


Xion here is appearing as her hooded-variation. By this stage in the game she would be unhooded. No limit bar.


Here depicts an event from the game. However Axel's face in the speech pane looks like it's taken from a pre-rendered model. In the game, it looks more illustrated.




The above images show the game to have a vastly different HUD from previous screenshots. Most likely the earliest public-seen build of the game, it shows characters without a LM bar that later prototype screens possess and the HUD and subsequent character icons are different. The HUD is also missing a the Command Menu in the left-hand corner of the screen. It also appears that the boss has been 'locked on', however there is no "Lock on" text on the screen.