Recently I worked on a 1kb Tetris game, and I figured it'd be fun to embed little games inside 88x31s. Here they are! Each fit in under 700 bytes, so you aren't bloating your website any more than adding a normal button.
Snake game
<iframe src="https://rinici.de/buttons/snake" width="88" height="31" sandbox="allow-scripts allow-popups" style="border:none"></iframe>Approx. 600 bytes
Flappy bird
Initially was just going to be black and white rectangles, but I was able to have a little fun making the graphics for it since it turned out to not be a whole lot of code.
<iframe src="https://rinici.de/buttons/flappy" width="88" height="31" sandbox="allow-scripts allow-popups" style="border:none"></iframe>Approx. 700 bytes
Bouncy DVD logo
Will you catch it hitting the corner? Despite the looks I'm not a maths nerd, so I have no idea if it is actually possible for each random coordinate. Good luck!
<iframe src="https://rinici.de/buttons/dvd" width="88" height="31" sandbox="allow-scripts allow-popups" style="border:none"></iframe>Approx. 500 bytes
Sand toy
<iframe src="https://rinici.de/buttons/sand" width="88" height="31" sandbox="allow-scripts allow-popups" style="border:none"></iframe>Approx. 500 bytes
License
You're free to embed these in your website! As with the website's source they are also available under the Apache License, version 2.0.