Just listen. How much of the gameplay can you see?
Designing the sound scape for a game is like appealing to another set of "eyes" that look in all directions simultaneously. What I mean by this is, when you're playing a game your eyes will focus on different parts of the screen for different reasons. However, your ears are open for anything. So depending on a game's visual design (screen scroll, screen size, cluttered visuals, etc) intelligently designed sound effects can give the player contextual, crucial information. Important interactions and incoming hazards generally need very clear sound effects that rise to the forefront of the sound scape.
If you think about it, sounds help you feel the actions as much as visuals do. Back in the NES days, developers of games like Super Mario Bros. and Mega Man had to do everything with so few audio channels, processing power, and so little audio fidelity. So the small range of sound effects that are in these games must be very important. Mario's JUMP, the primary mechanic/function, has its own sound effect. You never question whether you've made a JUMP because your ears will back up your eyes. After all, our brains process audio stimuli (reflexes) much faster than visual stimuli. Furthermore, when you land on an enemy, you get a sound effect to help you understand exactly when the collision occurred. These are the important interactions.
Indie game examples:
Can you tell what's going on? Do you hear distinct actions? Or mostly music?
- Super Meat Boy: The sound effects for player actions are really backgrounded to the music. When the game speed is so high and there's no buffer for inputs, seeing collisions/positions of the fast moving Meat Boy can be extremely difficult. For example it would help if there was a distinct sound effect for wall collisions so players know exactly when they can wall jump.
Difficulty and Unity
Difficulty is a tricky area in game design. Challenge is tied to player agency, or ability for a person to to change the game state, affect the world, and reach the goal. Even if a game is very engaging, if the challenge falls short then some players will stop playing. Allowing a player to maintain this flow zone requires a game with variable (player controlled) difficulty. The more linear a game challenge, the smaller the flow zone. The smaller the zone, a player is less likely to be satisfied with the game.
Super Mario Bros. is designed in layers of challenge. The core (mandatory) challenges involve maneuvering around obstacles/enemies to make it to the end of each level before time runs out. This core layer is variable. There are alternate paths, powerups that allow the player to undermine challenges, the RUN mechanic for faster gameplay, and plenty of emergent variation that result from player actions (interplay. see here).
Then there are the auxiliary (optional) layers; coins and secrets. While playing to the core challenges, players are free to increase the challenge by grabbing coins and discovering secrets. These optional layers of challenge really help push and pull the player in new directions creating a game that greatly encourages a freestyle playstyle. This freedom of play makes it easier for players to stay in their flow zone.
Miyamoto: Let's say, for example, that there's one action in the game that the player can perform easily. Then let's add another simple action. These actions may be simple in themselves, but when the player is required to do them both at the same time, it becomes a whole lot more tricky. [Iwata Asks]
The genius of designing levels in layers is the flexibility of challenge built on a relatively simple foundation (the core gameplay). Because the challenge is there should you choose to meet it, the core game can maintain a consistent, moderate level of challenge and organic unity. In Super Mario Bros. every level looks like real place in the Mushroom kingdom.
Many indie games mostly avoid layered level design. I don't blame them. The more layers the more difficult levels are to create. This means that the challenges in many indie games are fairly straight forward and linear. This reduces the amount of variation and freestyling the player can bring to the game while shrinking the flow zone. This isn't necessarily a bad thing. Music rhythm games are generally very linear games.
When indie developers design games with linear levels, there's a tendency for them to be too easy (due to a lack of variable difficulty) or far too hard. The more emergent the core dynamics of a game system are and the more strict/linear the challenges, the more the gameplay becomes stressed. In other words, if there are 100 variations for a character's JUMP and only 5 or so will be successful at a core challenge, then the balance shifts over into puzzle/riddle style where the challenge comes from weeding through extraneous complexities/possibilities.
In general, it's much harder to design layered levels than to design a hard level. Anyone can make a level hard. Just randomly arrange some game elements to create chaos; purposefully put frustrating challenges in levels that are difficult to learn or overcome; fail to playtest and tune a level; create challenges that require a precise execution of mechanical nuances and/or glitches and your game will probably be very hard.
When indie developers work to increase the difficulty of their linear linear, sometimes the look and feel of the game gets sacrificed. The levels look less fictionally coherent or fail to represent an organized aesthetic.
Here's a list of linear, strict, and or difficult indie games.
- I Want To Be The Guy: A well known punishing platformer, nothing it what it seems in this game. This game isn't about self expression or freestyling. It's about survival. And when everything is a look-alike mixup, the best strategy is to memorize everything and trust nothing. This game is design to break spirits. Also notice how the organic unity of the game is thrown out the window. Riffing off of various themes and challenges from other games, this game is a hodgepodge aesthetically. If you want to be the guy who beats these kind of games, good luck.
- Hard Mario Mods: Hardest Mario Level Ever, Kaizo Mario World: These levels strip away the capacity for freestyling (one of the Mario series' greatest strengths) making these levels extremely difficult and counter intuitive. You must know every nuance of Mario's mechanics to survive. Furthermore, the organic unity of the Mushroom Kingdom is sacrificed for the purpose of making difficult levels.
- VVVVVV: You can either move or flip gravity. The levels are pretty cleverly designed considering how limited the mechanics are. Still they're also very linear.
- Super Meat Boy: This game does have some layered level design. There are optional warp zones and bandaids to grab. But these elements aren't in every level. The levels tend to be very linear though some have elegant solutions and alternate paths. The developers also designed some bandaids to be more accessible with unlockable characters but this doesn't qualify as player controlled variable difficulty.
- Flood the Chamber: This game entirely exists in one large screen. Make your way from the bottom to the top before the chamber floods.
It seems that I've targeted a lot of platforming indie games in this series. Though I play a lot of indie puzzle games they tend to avoid may of these pitfalls because of the nature of puzzle games. These issues mainly apply to action games, and in the indie space platformers and side scrolling shooters are popular. If you have more examples or comments to add, feel free.
In the meantime, I'll be working on polishing out that indie feel from my own games.