There's a Flappy Bird clone for the GameBoy, in the form of a 32kB ROM. [0][1][2]

This isn't to downplay this Android-based project though. They aren't claiming to have written the most compact Flappy Bird clone.

[0] https://laroldsjubilantjunkyard.itch.io/flappy-bird-gameboy/...

[1] https://laroldsjubilantjunkyard.itch.io/flappy-bird-gameboy

[2] https://www.youtube.com/watch?v=m839Vg_qXzM

I'm honestly surprised at the 100k figure. In my mind it should be possible go far lower. 10k sounds vaguely realistic.

if you're willing to compromise on the graphics and just get the core gameplay, I reckon you could do it in a 512 byte x86 bootsector.

I think it can be optimized quite a lot by not using a stock PNG decoder library, because all images are quite simple and can be generated from non-pixelated smaller sprites (many images are pre-scaled by 2x, which can be done during the postprocessing) or from a simple algorithmic code.

Right. I meant with the graphics though.

Weirdly, I think the challenge would be more difficult going to Android than adding graphics while keeping the size down.

It would not at all surprise me to see a near perfect Flappy Bird under 4k (graphics and all) as a PC .com

I'd be curious to see what the minimum size of a simple C program would be. Say something that displayed a pixel that bounced up and down as you tapped.