Part 1 - Interface
Oblivion is perhaps the biggest disappointment of 2006 when it comes to computer games. What was supposed to be the RPG of the Year has turned out to be nothing but a dumbed down console game designed for kids and people with no attention span whatsoever. The only even remotely redeeming quality of the game is the graphics engine and the graphics of the game are mediocre at best. To add insult to injury, Bethesda has short-changed PC gamers, the people WHO MADE The Elder Scrolls what it is by releasing a half-assed console port.
Compared to Morrowind, Oblivion's interface looked like it was designed by an 8-year old. What could be done in two clicks of a mouse button under Morrowind now takes 5 or 6 clicks under Oblivion.
For comparison, here is a screenshot of the standard Morrowind interface :
All of the above windows are brought up simultaneously by clicking the right mouse button. So with a single mouse-click, the player has access to his or her inventory, stats, magical items and effects and the map. Furthermore, all of the items are on the screen at once. Granted, Morrowind's interface had it's flaws. Potions were hard to find because of the way items in the inventory were sorted and it could get cluttered at time. But Morrowind's interface was useable.
Compare it to this :
Bethesda took Morrowind's perfectly usable interface and replaced it in favor of this monstrosity. There are so many usability issues that it's hard to know where to begin.
The first and most glaring flaw with Oblivion's interface is the use of nested tabs, otherwise known as tabs within tabs. Nested tabs are a big no-no when it comes to PC interface design. Anyone who has taken any basic college level class on interface design should know that nested tabs are bad design. They add unneeded complexity to the interface design and require the user to take more steps to preform various actions.
2.Inappropriate use of controls/choosing the wrong control for the task at hand
Bethesda, in their infinite wisdom, decided that it would be a great idea to use gauges and other images in place of tabs. To the user, it is not immediately apparent that the compass or the health bar are both tabs because they already serve a purpose. Controls should not serve a dual-purpose and tabs should be used for a tabbed interface. This is no different than if a program made progress bars or check boxes into tabs.
3.Lack of Tooltips
In Morrowind, there were tooltips everywhere. Tooltips are those little boxes of text that pop up when you hover your mouse over an object that provide the user with help or useful information. There are none in Oblivion where you would expect them. Did you get cursed by that monster? Want to find out what effects that curse has on your character? An icon pops up in the top-left corner of the screen with a cryptic image that really does nothing to identify to a user what the effect is. One would assume that hovering the mouse over this icon would clarify for the user what this icon represents. But it doesn't. Instead, the user has to navigate through the nested tabs until they get to the appropriate page to find out what effects are active on their character.
In Morrowind, if you, the player, wanted to drop an item, you clicked on the item in your inventory and then clicked again where you wanted to drop it. To pick up an item, you either used the appropriate key (usually space) or you went into menu mode and clicked on the item and dragged it. In Oblivion, none of the above works. To drop an item, you must hold shift and then left-click on the item in question. First off, in every other computer program, holding down shift while selecting items is associated with selecting multiple items. Not so in Oblivion. Second, the steps required to drop items are not immediately apparent to the user. To add insult to injury, the physics system makes it near impossible to place an item and/or decorate a house because, inexplicably, when placing an item, the cursor is locked to the camera.
5.Inappropriate Font Size
It's fairly obvious from this mistake that Bethesda only put effort into the console version of Oblivion. Computers have a mouse and keyboard. An interface should not be using size 36 font that allows for only 6 items to be displayed at once and customers shouldn't have to rely on mods just to fix something in the interface that, if Bethesda had chosen to care about PC gamers, could have done in 5 minutes.
Morrowind had 10 hotkeys (of which one was permanently mapped to your characters fists). Oblivion has only 8. Computers have a keyboard. A 104-key keyboard to be exact. Having only 9 usable hotkeys in Morrowind wasn't bad because the user could access their spell list with a single right-click. In Oblivion however, the user could have to go through as many as 3 actions just to get to that spell list, which compounds the problem of limited hotkeys. Again, adding insult to injury, there is no immediately apparent way to access the hotkeys. A user is not going to know that holding down the numbers for the individual hotkeys allows them to be mapped without going through the tutorial. An interface SHOULD NOT require a tutorial just to be able to grasp it's basic functionality.
As stated above, most computers have a 104-key keyboard. So why in the world did Bethesda decide to hardcode so many actions. Want to map your journal to the J key? Sorry, you can't. Want to map the spell list to the M key? Sorry, you can't.
8.Inappropriate use of artwork
The artwork of an interface should not take up half the screen. This includes the full 3D rendering of the player's character. Had Bethesda chosen to stick with a paperdoll approach, more than half the screen could have been freed up to be used by the parts of the interface that matter. Instead, we have a huge rendering of the character taking up valuable screen real-estate for no purpose other than to look pretty.