Grid view in SimCity 5. This is NOT what the game is supposed to look like, you need to see terrain and landscape
Green Terrain View. THIS is how the game is supposed to look like. You can see the terrain textures

Cause

This issue happens primarily to people who installed a physical copy from Disc (CD/DVD) and something went wrong in the update process, and they are stuck in grid view and cannot toggle grid or toggle land.

Solution (Confirmed Working)

Only solution is to UNINSTALL the game and RE-INSTALL it.

How to Uninstall

You can try right clicking on the game from your Origin library and choose to uninstall. But sometimes that doesn't work. Go instead to your windows Control Panel and uninstall through the Programs and Features menu.

Installing Again

Launch your origin account and you will be able to install it again from your library. You will have to download all the game and process large files, so this can take a while depending on your internet connection

NOTE: Even though you got the game as a physical copy, you will still be able to install it digitally through origin. You DO NOT have to purchase the game again. It should be in your Origin library and you can download it from there whenever you want.

Non-Working Solutions

These solutions didn't work for me, but you can try them anyway:

Re-Installing from Disc (Did NOT Work - had same problem again)

Right clicking on SimCity from Origin and choosing to repair the game (Did NOT Work - said all files are up to date)