hehe, regarding steam, I can't make promises but I'll say "soon, and hopefully sooner than you expect!"
Honestly, I was really prepared to port Bossgame to a gamepad! While I was designing the mobile version, I would often test it with an XBox controller (and occasionally keyboard) to see how it felt, and it works well! The left & right side design maps very easily to a controller - by default, Sophie (left) is controlled by the DPad, and Anna (right) is controlled by the face buttons. Similar to the mobile version, the gamepad will take a minute to get used to, but after that it should start to feel natural pretty quickly. IMO, the keyboard is a little less natural, but it still feels good to play.
The biggest challenge I've faced so far was writing the button remapping code! I've never written button mapping for my games, and I didn't need to do it for phones, but now there's just a lot to take into account. Plus, I am working with an input library that unfortunately threw me for a loop. I've got it working now, but it took longer than I would've liked, and it was not a fun part of the project... Hopefully I can avoid that problem in future games since I've solved it once!
Thanks for your question :D