Link to game file for PC:
Insert the link to your game file if it's for PC
(PC is a conventional computer and it uses Windows)

Link to game file for MAC:
Insert the link to your game file if it's for MAC
(MAC is a different type of computer and it uses another operating system, not windows)

Link to game file for Mobile:
Insert the link to your game file if it's for Mobile
(Mobile = cellphone and etc)

Platform

Online
Check it if your game can be played online
(No need to download it)

Downloadable
Check it if your game needs to be downloaded to be played

Mobile
Check it if your game runs only on mobiles
(Mobile = cellphone and etc)

Hope this helps you.