itch.io

It was made in Game Maker: Studio, I might make the base available early 2017 but the thing is such a hard coded mess I'm not sure if people would find it useful at all

There's a Mercy option, yes

It's not the most apparent way but yes there is

I used Game Maker Studio for this, no premade programming nor hacking done

The looping doesn't work quite right in HTML5, the .exe version does it better, there's also a few differences of how Windows and HTML5 versions work, but this is the closest I could get for the web.

Best of luck with that, takes some effort to do something like this on your own

Used Game Maker Studio and a lot of time trying to replicate Undertale the best I could, I didn't have any code from the game at all.