You need an Internet connection to initially download content. Once Modern Warfare Remastered has been downloaded, you do not need to be connected to the Internet to play/launch the Single Player Campaign or play Multiplayer locally. Will Call of Duty: Modern Warfare Remastered come as a separate disc?
You can play the game offline, but there are several things you need to do first: Install MW3 via disc or download. If you're using a disc, you'll be prompted to download a 70+GB patch. If you purchased a digital download, skip to the next step.
Subway Surfers is an incredibly popular game that almost everyone has played or seen at least once. The mobile version of this game is familiar, and the game is commonly used with videos to keep people entertained. Poki has this game in a web version, which is just as fun as the mobile version.
While this site offers a variety of games from many developers, the quality of the games can be inconsistent, with some lacking clear (or any) instructions, which reduces the fun for the site.