this is so creative and the result is really cool! I love how the two energies moving towards each other gives each bit of movement a driving narrative tension (not sure if that's the best way to phrase it)
Tunnel uses two bitsy games side-by-side. I created them each individually in bitsy then used the <iframe> tag in my own simple html file to embed both files side by side. To make the two games sit flush with each other I edited the style of the bitsy files to remove margins etc. I also flipped the controls of the right game and added event listeners to the window parent as opposed to the document. There may be a better way to redirect input to each one as the current implementation required the player to click on the parent document hence the 'click here' text. It was great fun poking around inside and I hope to do something a little more interesting with the concept in the future. I liked the simplicity of having two 'energies' both flowing through the rails coming closer and closer and when they touch the game ends.