Iji title screen['The Interactive Palette' is a biweekly GameSetWatch column by Gregory Weir that examines the tools and techniques of the digital games trade with a focus on games as art, using a single game as an example.]

One of the nebulous terms that game journalists seem to use to taunt developers is "replay value." According to many reviewers, a game's not very good unless it's fun to play multiple times. This is partly an issue of economy; a game that bears replaying provides more hours per dollar than one that does not.

It's more an issue of breadth, however. Replay value comes from many things, and one of them is the ability for the game to let players have a different experience each time they play. This breadth of experience means that players who enjoy a game the first time can experience more entertainment from the game by replaying in various ways.

Replay value's not just a buzzword. It means that players that like a game can see more of it without the developers creating an expansion pack or a sequel. It increases the longevity of the game in the hearts of individual players and, on a more mercenary level, increases the amount of time word-of-mouth can spread about the game.

There are three basic kinds of replay value. The first is the ability to reexperience previous game content, in relatively unaltered form, with a minimum of fuss. The second is the ability to reinvigorate the game's challenge by making it more difficult or adding constraints on the gameplay. The third is the ability to reimagine the gameplay by changing the goals or the style of the game on a second play-through. Each of these three has a different appeal to different players.

There's really no excuse for a developer making a large game to leave any of these three types out. Each of the three kinds of replay value — reexperiencing content, reinvigorating challenge, and reimagining gameplay — can be added to a game with little additional effort.

Daniel Remar's new indie game, Iji, is a good example of a game that gets this right. Besides single-handedly creating a strategic platformer to rival Flashback and Turrican, Remar included an array of features to enhance Iji's replay value.

Iji is a game with graphics inspired by Another World/Out of This World and a storyline involving alien invasion and nanotechnology. The main character, Iji, is a young woman who happens to be visiting her scientist father's research facility when aliens attack and make the building their base of operations. Iji is badly injured, and human scientists manage to rebuild her with alien nanotechnology as a tool of resistance against the aliens. As the game progresses, Iji can upgrade her abilities and learn more about why the aliens have attacked and how humanity can be saved.

Iji loading screenNanofield Reboot

The first kind of replay value is the ability to easily reexperience familiar content. Iji does this in a number of easily reproducible ways. One of the simplest is allowing the player to skip cutscenes. Most cutscenes and conversations in Iji can be skipped by hitting the escape key, which means players who want to replay without rereading can get to the game faster. Additionally, Iji allows level selection after the game is beaten once, which means that if a player especially likes, say, Sector 6, she can replay just that level without having to keep a specific save file around.

Each of these techniques — skipping cutscenes and replaying levels — is easy to implement. Additionally, games with separate cutscenes often benefit from letting the player replay interesting cutscenes. One thing Iji doesn't do is provide a "New Game +" feature like in Chrono Trigger, where a player can start a new game with characters at the experience level they were when the game was previously completed. Developers can add these features to games with minimal expense of time and effort, and satisfy players who want to go through the game's story again.

Iji backstabTeching

Another kind of replay value is the ability to reinvigorate the challenge of a game for an experienced player. Players who have completed and enjoyed a game typically have gained a high level of skill at the game. These players often want to experience a harder version of the game. Iji, like many games, offers variable difficulty levels, which is an excellent start. A player who has beaten the game on "Normal" mode can replay on "Hard" to regain the sense of challenge that she felt the first time through.

Iji also offers some less common features in this area, though. First, there is in-game support for time trials on each level, which provides an "official" way to record time for players interested in speedrunning the game. Second, the game records various statistics like kill count and nanocracking success rate, allowing players to challenge themselves to achieve a high score. Finally, there are a few hard-to-perform "hidden skills", such as "teching" out of attack knock-back, that let highly-skilled players gain an advantage but don't penalize less-skilled players for not mastering them.

Difficulty levels are already standard for most video games. Providing an in-game timer is less simple than it seems at first; decisions need to be made about what happens to game time if the frame rate lags and whether to include cutscene time in the official count. The feasibility of including advanced techniques differs from game to game, and does require thought about game balance and the introduction of bugs and exploits.

Iji poster shotCybernetic Endurance

The last sort of replay value is the reimagining of gameplay. The most common form of this is the ability to customize the player character's abilities. Iji's title character can upgrade herself at cyborg stations, spending points to enhance various abilities she possesses. During multiple play-throughs, a player can choose a different upgrade path, providing her with a different play experience depending on which abilities she makes her focus. This option, though, is really only applicable to games with roleplaying-game-style character advancement.

Iji also provides a hidden poster in each level, however, and this is something that can apply to any game. The addition of collectible secrets can provide an alternate goal; instead of following the central plot line, the player can take time off to search levels for things she missed the first time around. An alternative to Iji's approach is to have achievements or trophies that are awarded for tasks that are outside of the central gameplay, such as performing a certain stunt or finding a certain number of collectibles. The achievement system is the simplest option, as all that is required of developers is to record and monitor certain statistics about the player's actions. Additionally, both the PlayStation 3 and the Xbox 360 already support achievement tracking as part of their online services, and Valve's addition of them to Team Fortress 2 is likely to make them more popular in PC games.

Iji is a game which provides all three kinds of replay value, by allowing players who have completed the game once to play it again without fuss, to make the experience more challenging, and to change the way they play the game. Remar, by single-handedly creating a freeware game with such replay value, has set the bar quite high for commercial developers.

Luckily, there are simple techniques that allow developers to satisfy each of these types of replay without expending much work. Players who enjoy the game will thank developers for including ways to extend their fun, and their enthusiasm will lead to more people interested in the game. There's little excuse for developers not to include these techniques in their game design.

[Gregory Weir is a writer, amateur game developer, and software programmer. He maintains Ludus Novus, a podcast and accompanying blog dedicated to the art of interaction. He can be reached at Gregory.Weir@gmail.com.]