Well, I made everything in those screenshots with 96 different 8x14 1bpp tiles and 12 colors (the train engine and rail split swap back and forth because they both use like a third of them, and the video uses a different tileset and palette). Really, you'd have 256 of those tiles and 16 colors at a time in a game but I'm working with restrictions by the lead developer on the game. A lot of older stuff, and a few more recent games, like to use the default ASCII graphics, but they're easily changeable. Once you get used to the environment, you can figure out ways to make the limitations less noticeable though :p
In the near future, hopefully MegaZeux is moving away from some of the worst restrictions (the palette, the weird tile size, the restricted 80x25 tile window size), but the scripting language seems to be the main focus at the moment.