Perspective

Camera perspective is very important for games, as it's the view of which you play the game.
Different styles can be found.

Today I will talk about 2D, 3D, Isometric, Top Down.

2D games are often seen from an side-on, such as the classic Mario or Sonic view.

2D games can be layered but as the camera is on the side, it all seems as one, this can be found in UbiArt games like Valiant Hearts: The Great War.

Isometric is different to top down as it is on a more diagonal angle rather than a straight angle.
The classic isometric view can be found in Diablo, however it can be found in other games like Bastion.

3D games can be from the first person or the third, Halo is a first person game, Alice: Madness Returns is a third person game.

Top down views can be seen in classic JPRG overworld sections like Pokemon games and shooters like Galaxian.

Different perspectives are often considered better for some genres than otheres, for example making a side-scrolling RTS isn't as effective as the isometric style.
Or Skyrim as an isometric game wouldn't be the same as it is in its current 3D form.