Coincidentally, I've been thinking about this project today's morning. One of my main problems is, I wasn't given any tips on how should the most basic aspects of the game look like. While implementation of semi-realistic Earth physics for a human character shouldn't be hard and I can suppose Obi will be most familiar with tilesets made of a main image and mask, I still need things such as tile size (I recommend 32x32 or 48x48), character mask size (something like 16x64 seeing your sprite? for comparison, in JJ2 it's 24x24) and how many pixels are there per an in-game meter (depending on how tall the character is, probably something around 37?).