Well, here we go.
First, let's say what a game-play loop is. It's a segment of game-play that is repeated, often with minor changes. It's like a formula, but really it's more akin to an episodic or formulaic TV show or even a pop song (or poem). It's a structure or flow of game-play actions that's repeated, but the background, setting, the details, all change. It also has a rather static amount of time. Twenty-six minute TV shows, three and half minute pop songs, 'rounds' of game-play (because it's like a 'loop' so it goes in a 'round'). That's a game loop (if it's a 'core' game loop, it's heavily repeated and important).
So, what makes a game-play loop 'fun' and 'meaningful'? It should be an action or series of actions worth repeating, it should be 'Autotelic'. The Author of "Flow", Mihaly Csikszentmihalyi, basically says this occurs when the action has challenge that matches the player's skill (I'm paraphrasing). It also contains significant feedback to the user of how well they are performing the actions, and the action has room for considerable mastery.
|This is a common graph of 'Flow'.|
An engaging loop is not just this combination of skill and challenge; it's also how this occurs over time. In a way, it mirrors the story progression of the Mono-myth or the Hero's Journey. It sets the stage and initially hooks the reader/viewer/user/player; then it has rising actions, and ends with a climax, and then a denouement. This tends to be like a fractal in nature, where individual actions of the game loop, the game loop itself and the overarching game experience, all follow this arc.
In a game loop this kind of has several phases (This is not a five step process by any means, but this is simply how I remember it. I should probably do a more in-depth post on graphing engagement and intensity)
1. Tell the player what they are going to do and the goals (sets the stage)
2. Throw the player into the actions (Initial high point of stuff happening and player figuring it out.)
3. The player gets better at the actions, so if the loop is that you shoot all the enemies, you are getting better at shooting. (these function as the rising actions)
4. The player has a high stakes epic moment, they are prove they are a hero (this is the climax)
5. The player is shown how well they did and the results of their actions are shown to them (denoument)
|There is a whole bunch of stuff I can say about engagement curves, but this will do for now.|
Now, core game loops in successful games have often had some interesting commonalities. Often when we talk of core game loops we discuss mobile and free to play and stuff; But my best example actually comes from triple-A-games.
First person shooters are an old guilty pleasure of mine. So, my example is a comparison of Counter Strike (from modders and those Valve folks) and MAG (from Zipper Interactive, 'pour one out'). I actually really enjoyed both games, but there was a pretty significant difference between them. The length of play. Counter-Strike has a three minute round, and if it actually takes three minutes it takes forever. MAG's rounds were around 14 minutes up to 25 minutes (if I remember that correctly). Now as far as popularity is concerned, there are a lot more CS servers than MAG servers right now (MAG was forced to shut down this year).
|Both are good games, but have a stark difference in their game round length.|
Simply, MAG tried to push a really long core loop onto a really fast game. How many 25 minute rounds are you going to play*? Maybe two. But with Counter-Strike you can always play one more three minute round, even if you have been playing for the last two or three hours. This dissidence between the round play time and the core game loop I think hindered the popularity of MAG.
You also see this three to five minute round (or short round) repeated in many games where players are expected to repeat multiple rounds**. Most social and mobile games have tasks that take around five minutes to complete. The default setting in most fighting games is rarely over three minutes per round. This short game loop often tends to facilitate repeated play.
Is a short game play loop fun (or better than a long game-play loop)? It might be more fun, and it definitely seems better than a long game-play loop. But it really depends on the goals of the game. Shadow of the Colossus doesn't have a short game play loop. It's a wonderful game. It's a wonderful game for what it's trying to be.
|This has a slower game loop and that's good.|
|The structure and timing of musical experiences can give many insights into games.|
Going to music, LCD Soundsystem's 45:33 is a 46 minute track commissioned by Nike (through the add agency Cornerstone) as something to listen to while running. That track is excellent for that, but it is not a good track for a chart topping single. However, portions of it was later remixed into "Someone Great" and other tracks on the critically acclaimed record "Sound of Silver". Having a short song or a long song was a decision by James Murphy for the task he was making a song for***.
The length of a core game loop is a decision the designers need to make. It needs to serve the game and the experience they are trying to deliver. Short game loops are great for that short, fast and repetitive play. Long game loops give a longer feel, it can be deeper, it can be more contemplative, or it can be for a marathon. They are different and have a different appeal. Pop music sits around the three or four minute mark because a lot of people like that, but a lot of people liked "American Pie" (it clocked in with 8:33').
... But the money seems to follow the short game loop.
*DotA and LoL immediately seem to work against this, but I'm not convinced. Much of the game-play in these games has been described as a sort of competitive vs MMORPG. In a sense it's kind of a game about whom can grind and optimize a character the best in the shortest amount of time. Under this analysis a 30 minute round for a game that is essentially about the meta-game of optimization is actually relatively short when compared to the number of hours a player would expect to sink into an RPG.
** This three to five minute round is not a hard rule for creating an engaging game; the tempo, or speed at which these games are played effects the optimal length for a good round. In general, real time competitive games tend to be the shortest and turn based strategy games tend to be the longest (for example, a 15 minute turn in Civilization V can be very engaging). I think MOBAs might be even longer, but I honestly haven't gotten much into them so I can't make a good judgement. I really need to discuss tempo in games (and we've known about it for a while), but that is beyond this article.
*** Or he wanted to invoke a pavlovian effect in the listeners of Sound of Silver who are also runners.