Thanks! ^-^
I just thought of an amazing idea to add on to this concept.
In the picture, it appears like you can only add 4 wide tiles (or, 8 medium-sized tiles). But imagine if there was a scrollbar just to the left of that middle divider. With a vertical swipe of your finger, you could scroll down and reveal more tiles underneath. So the tiles section could scroll up and down!
The "Recent Apps" and "Recent Files" sections could work the same way too, why not? It would show 8 recent apps instead of 4, and you'd swipe up to reveal 8 of your recent files, and swipe back down to go back to your recent apps. Obviously, this would be more ideal for touch-screen users. Mouse and keyboard users would probably just want it the way the image shows (or, have a visible scrollbar and have part of the "Recent Files" text pop out from the bottom, so it lets users know that they could scroll down there). But for touch-screen users, the two divisions of this start menu could potentially allow for vertical swipe gestures in order to view more content in less than 1/3 of the entire screen.