In case any devs are still thinking about what tools to use — or want to stretch their legs by trying something new — please consider giving Mini Micro a try!  It's a free neo-retro virtual home computer, and while it supports a much higher resolution display, if you scale it down by a factor of three, it comes out just about right (see this blog post for details).

For controls, I would recommend using the `input.axis` method to get directional input, which lets the user use WASD, arrow keys, or a d-pad if they have one.  For button input, check for several different keys and buttons as shown in this example, so that again, they player can use either keyboard or a d-pad to play.

Good luck to the participants, whatever tools you use!