For school, I made a few embedded games that work on any webpage, and they are hidden as bookmarks .

To install, make a bookmark, name it something stealthy, and change to url to the code under the name in the quote things.
To run, click the bookmark to embed it on your current page.
Going to another page will make it disappear. It is recommended to leave a page just for the games.
Some are hidden in corners that you need to put your mouse in.On some sites, the corners might be a bit off.

Example:
Edit the text easily on any page without inspecting:

javascript:void((function(){document.body.contentEditable='true'; document.designMode='on';})())

1. Copy the above code. (javascript:void…)
2. Make a new bookmark (by bookmarking this page).
3. Right click (Control-Click on Mac) the bookmark, and click edit.
4. Rename it to something not suspicious.
5. Change the URL (the page it is bookmarked to) to the above code that you copied (delete the existing URL and paste the code).
6. Click the bookmark after exiting the editing, and temporarily edit the current page that you are on by clicking in some text and typing.

Pokemon FireRed:
Move mouse to the bottom left to see the game.
Remember to save on the in-game menu by pressing start on the overworld, and then pressing A on save.
Controls:
Z is B, X is A. Arrow keys are D-pad/Movement. Enter is START.

javascript:void((function()%7Bif(window.fire){return};window.fire=true;var i%3Ddocument.createElement(“iframe”)%3Bi.src%3D"https://jsemu3.github.io/gba/launcher.html%23pokemonred“,document.body.appendChild(i),i.width%3D240%3Bi.height%3D160%3Bi.frameBorder%3D0%3Bi.style.position %3D ”fixed“%3Bi.style.bottom %3D 0%3Bi.style.left %3D 0%3Bi.style.zIndex%3D”1000"%3Bi.style.opacity%3D0%3Bi.focus()%3Bi.onmouseover=function() {i.style.opacity=1;i.focus();};i.onmouseout=function(){i.style.opacity=0;};%7D)())

Splix.io:
Hidden in bottom right corner.
Controls: arrow keys
Might take a few tries to connect, works great after.

javascript:void((function()%7Bif(window.splix){return};window.splix=true;var i%3Ddocument.createElement(“iframe”)%3Bi.src%3D"https://splix.io/“,document.body.appendChild(i),i.width%3D300%3Bi.height%3D300%3Bi.frameBorder%3D0%3Bi.style.position %3D ”fixed“%3Bi.style.bottom %3D 0%3Bi.style.right %3D 0%3Bi.style.zIndex%3D”1000"%3Bi.style.opacity%3D0%3Bi.focus()%3Bi.onmouseover=function() {i.style.opacity=1;i.focus();};i.onmouseout=function(){i.style.opacity=0;};%7D)())

UNDERTALE (Sans Fight):
Hidden in bottom right corner.
Controls: arrow keys, and z to select, x to go back.

javascript:void((function()%7Bif(window.sans){return};window.sans=true;var i%3Ddocument.createElement(“iframe”)%3Bi.src%3D"https://jcw87.github.io/c2-sans-fight/“,document.body.appendChild(i),i.width%3D320%3Bi.height%3D240%3Bi.frameBorder%3D0%3Bi.style.position %3D ”fixed“%3Bi.style.bottom %3D 0%3Bi.style.right %3D 0%3Bi.style.zIndex%3D”1000"%3Bi.style.opacity%3D0%3Bi.focus()%3Bi.onmouseover=function() {i.style.opacity=1;i.focus();};i.onmouseout=function(){i.style.opacity=0;};%7D)())

Super Mario Bros. (NES):
Hidden in bottom left corner.
X is B, Z is A. Arrow keys to move. Enter is Start.

javascript:void((function()%7Bif(window.mario){return};window.mario=true;var i%3Ddocument.createElement(“iframe”)%3Bi.src%3D"https://trippproxy.github.io/mario.html“,document.body.appendChild(i),i.width%3D256%3Bi.height%3D224%3Bi.frameBorder%3D0%3Bi.style.position %3D ”fixed“%3Bi.style.bottom %3D 0%3Bi.style.left %3D 0%3Bi.style.zIndex%3D”1000"%3Bi.style.opacity%3D0%3Bi.focus()%3Bi.onmouseover=function() {i.style.opacity=1;i.focus();};i.onmouseout=function(){i.style.opacity=0;};%7D)())

I might make more games for this list. If you need help or have ideas, just reply.

What Browser does this work on

they dont work

not for me either

its jsemu2, not jsemu3

A

These do not work which browser do you have.

it don't work

will it work if they got blocked?

doesnt work

Only the first one works. Please fix this and add more!