Let's say you have a game like flappy bird. Basically zero extra features. You go for the high score and that's it. Somehow it becomes one of the most downloaded games ever. I'm planning on making a game similar to that. But I could add extra features to it. These include temporary powerups, permanent upgrades, levels, story, maybe bosses, challenge modes, achievements, and so on. How important are extra features to you, and when do you prefer a barebones game vs. a game with lots of extra features?

Coming up with extra features is easy. The hard part is throwing out the ones that distract from the good parts of the game or only serve to complicate things without making it more fun. 

8 hours ago, Jordan Hoffman said:

I could add extra features to it. These include temporary powerups, permanent upgrades, levels, story, maybe bosses, challenge modes, achievements, and so on. How important are extra features to you,

Features, schmeatures. It depends entirely on the game. Complexities should be introduced gradually. Additional features can reduce user friendliness.

There's a famous French quote which goes something like this in translation:

Quote

It seems that perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away.
-- Antoine de Saint-Exupery

It's fairly applicable to game design. If a game isn't fun in its most basic form, adding more elements probably won't make it fun. And too many elements can overwhelm an otherwise fun game.

That's not to say you shouldn't add unique elements - just do it with care and attention to detail. A lot of games will choose to introduce them very slowly (say, one new game mechanic per chapter) to avoid overwhelming a new player.

To add extra stuff in after production you have to consider it during development. Structure your code in a way that allows new functions to be added in.

The best way I found to do this is to have each part of the game in it's own loop, then you can use the start menu to run those loops. This means treating each mode as a stand alone game for the most part.

As Indie developers we have to focus on quality over quantity, however it is a lot more fun to make games with extra modes.

On 2/19/2018 at 4:09 AM, Hodgman said:

The hard part is throwing out the ones that distract from the good parts of the game or only serve to complicate things without making it more fun. 

In one team these were known as "puppy drowning meetings".  It is difficult to kill good ideas, but just like a dog breeder, sometimes you need to get rid of good ideas so you can focus on the best ideas.

4 minutes ago, frob said:

"puppy drowning meetings"

That mental image is going to be hard to wash out of my head...

It really is what we are doing.  The goal is not to make a game with a lot of good features, a few good features, and a small number of awesome features.  The goal is to make a game filled with awesome features only and none of the rest.  If something is merely good, it is consuming resources that could be spent on something more awesome.

 Watch this. Hope this helps you a little bit