Hardcore Gamer: In game development terms, a “vertical slice,” is a gameplay segment of finished or near-finished quality that showcases all the planned features of a game to potential investors. At the start of a project, these are a massive sink for time and effort, since they essentially involve doing all the hard parts of finishing a game to complete one 10-minute section. Generally, they’re seen as a bad practice. However, toward the end of development, it’s a lot easier to pull assets together for a vertical slice. Of course, if you’re shopping your game around to publishers at that stage, you’re probably in a lot of trouble, but a standalone “vertical slice” can also serve as a strong alternative to a traditional demo.