Even though Daisuke "Pixel" Amaya's Cave Story looks like a much older game, he said in a GDC presentation today that the late 2004 release has found an audience even among younger gamers.
"Maybe it made a mistake in coming to the world too late," Amaya said of the game. "When the game was completed, and I thought only older gamers could enjoy this, but after this was released I realized many young ones seemed to enjoy it. Cave Story is perfectly capable of being enjoyed in the current market."
Amaya said the game's old school look wasn't totally a matter of paying homage to classic games, though. Rather the look developed partly because he was not skilled in the 3D modeling and animation necessary for most modern games.
"It's easy to start a game, but to complete a game is difficult," he said. "I decided to adopt the retro style to complete it more easily."
Amaya said he made the game's 16x16 sprites more expressive with a few tricks. The main character's red pants, black shirt and white face were all made so the character would stand out against different colored backgrounds. The large, expressive head and small, highly animated arms were designed for similar reasons, he said.
Amaya noted that it takes only very small changes in the background environment, such as dripping water in a cave or grass clinging to a cliff, to strongly differentiate different levels in a game. "It doesn't have to be extreme," he said. "You don't have to give up just because resources are limited."
Small touches can also increase the interactivity and liveliness of the enemies, Amaya said, pointing out the way an enemy critter opens his eyes as the main character approaches to show he's interested. He suggested designers should play prototypes, rather than relying on flow charts, to figure out what elements of character interaction were the most fun and how enemies should react.
Sound effects can help highlight elements of the animation and graphics, Amaya said, by adding a creak to a heavy door, for example. He encouraged indie developers to add as many sound effects as they can, to communicate these kinds of things to the player, because "the ears want just as much information as the eyes."
Background music can have a powerful effect as well, appealing to a player's emotion and conveying the state of the game to the player very efficiently, Amaya said. He gave the example of a desert boss in Cave Story that actually moves very slowly, but the high-powered background music "tells the player the crisis is coming," he noted.
The story in a game is important less in and of itself and more as a way of letting the player know they're progressing through the game, Amaya said. He also urged designers not to load up heavy story scenes in the front of a game.
"When a player starts playing, he wants to play the game," he said. "It can be an epic story, but don't have it all at the beginning. Let the player enjoy the game -- if he enjoys the game he will be playing the game, and that's the time he wants to know the story. Start with the game, not with the story."
Amaya stressed the importance of item drops to encourage players to kill enemies, rather than sneaking by them, and of having weapons in the game the level up with use, to encourage players to use them all. He also talked about creating levels such that players feel like they're figuring out how to defeat challenges on their own, but really the designer led them down the path.
Amaya finished his panel by showing the first public video of Cave Story's beta edition, which had an increased role for the Balrog boss, centralized the story around the character of Sue, and let the player control a frog prince for an extended period. When a friend told Amaya the beta's system of collecting coins to buy weapons was awkward and occasionally frustrating during boss battles, Amaya decided to start over from scratch and create the current version of the game.
During testing of this version, Amaya said he was surprised to hear testers demand a more difficult stage to finish out the adventure. This became Blood-stained Sanctuary, a level even he said he has trouble completing.
"I had the urge to create a more difficult [level during development], but up to this point I tried to suppress this feeling -- I thought it would be too difficult," he said.