Just gotta note one thing: simplicity in design isn't really a way to add design elements, it's a way to remove them. It's an approach which condenses and refines complexity and renders it intuitive. It is both harder and more rewarding than complexity, because it lies on the other side.
- Determine the core values of your concept and what players are engaging with and aiming for at various levels: second by second (combat, puzzles), minute by minute (level progression, tactics, equipment management) and hour by hour (story, strategy, replayability). What's important? What can you afford to cut for the sake of simplicity?
- Cull everything which is of little value to that core. Be merciless. If it doesn't significantly add to the core of the experience you're creating it is worthless
, however cool it might sound in isolation.
- You can also merge weak or redundant elements together to form stronger, more distinctive elements. Look for ways to merge entire systems such that you're left with a single, richer system.
- If two design elements don't interact much, find ways to make them interact or consider cutting or changing one of them. Rich interactions between different systems are a great way to get depth without apparent complexity.
- Rather than adding new elements or systems, look for ways to develop or exploit nuances of existing elements and systems which can make the game richer in an intuitive way. That's OK.
Here's something concrete. Stop adding content which has different statistics
; that's easy to do but it's boring as hell. Instead, add content which has different rules
. It's more work, but your players will likely find this easier to grasp - and more fun! Instead of a gun that does more damage but takes longer to reload, you can have a gun that's powered by sunlight and sets people on fire... and so on.
With Zelda, I could very easily believe they started out with sword combat and monsters, added an absolute ton of crazy stuff - immediately rejecting anything which was boring, or just changed stats, or whatever. Then they kept hammering at it until every single thing either ended up balanced, intuitive and unique or got cut.
A lot of it would have been cut. Polish like that is ultimately about being willing to throw away a lot of your work.
btw, the core of a game can be ridiculously simple and unimpressive. There are tons of successful games about just moving and jumping, or moving and shooting, or pressing buttons in time with music, or steering a car. There are major successful games simply about throwing stuff. Foddy's
made multiple games about moving your legs. You can make games about typing, or brewing coffee, or swimming. Anything goes.
If you want to make a simple idea strong or interesting enough to be the core of a game: make that simple idea in such a way that it's fun to engage with and rewards mastery, then add progressively harder, varied challenges related to that simple idea. That's all you need.