Mostly Unity and C#, I still use Python for bits and pieces (see my other comment). I made and make all the art myself, just painting in Photoshop, animating in the wonderful Spine by Esoteric Software (great tool that's worth every penny), and do all my video and audio editing in DaVinci Resolve (I used to use Adobe AfterEffects but the monthly fee was just too high for me). I also use Blender for any 3D work (I used to use Modo, but again, the monthly fee was too high).

Marketing for The Cat Machine wasn't too bad, I had an okay ground game with getting coverage from gaming websites and someone posts it on Reddit and for 2015 that was good-enough marketing for the time, more than enough to Greenlight the game. The voice actor is Scott Gilmour (@scottgilmour7 on Twitter) and I found him after listening to about 100 voice samples on all the different VO websites. He's fantastic! I don't share my sales numbers publicly, but Steam is about 70% of The Cat Machine sales, and about 25% is from the Apple Mac Store - where the game actually hasn't been published for about a year now, I need to get on that and reupload it. And games is right now my full time job, so no IP clauses needed negotiating, and my old employer back in 2015 was very chill about letting me work on my own stuff.

Hope that helps!