There are many fun stand-alone games, so there are many games worth playing again and again. However, considering that you can only play this game repeatedly for two years, you must consider whether you will be bored, innovative and persistent, and there may be some venting if you don't communicate for two years. So to sum up, I will choose fewer games. I recommend any of the following.
1. Grand Theft Auto v- is a game released by Rockstar Games. It has a completely open game environment and a lot of game content. It depicts the same values, world outlook and urban structure as our real world. At the same time, the plots and events of the three main tasks are also very interesting. Just like watching another American blockbuster, you can't go shopping in real life, just relax in a busy street by driving cars, planes and other means of transportation in the virtual world. PS: If you can get all kinds of MODS, you can play for several years.
2. Red Death Redemption 2, also called Big Cousin in the Wilderness, is also a game released by Rockstar Games and an open sandbox game, but unlike GTA, the background of this game is the wilderness era in the west. In the cowboy era, you can experience the thrill of riding in the wild in the west, be brave, camp or Grand Theft Auto. Everything is up to the players themselves, completely copying the world view and background story of the wilderness in the western United States, with a lengthy plot and unlimited gameplay. In summer, there are snow-capped mountains and trees to see the scenery, and you can still hunt and survive. All kinds of animals have AI. To copy the real environment, you should choose your own ideal or loyalty to the gang that raised them. The playability is very high, and it is also a work that never tires of playing.
3. The Elder Scrolls 5: Skyline is a role-playing stand-alone game developed and produced by Bethesda. It is also a huge world view and map, with high freedom of operation space, medieval style, multiple races as high as 10, and diverse occupations. After two years of idleness, you can complete full-time hegemony. In addition to the plot and killing monsters, there are also marriage systems and trading systems. For example, blacksmiths, alchemists, grocery stores, weapons stores, clothing stores, magic houses, armor stores, jewelry stores, stolen goods stores, shops, furniture stores and so on. At the same time, if this game can get all the DLC and all kinds of MODS in the first two years, I don't think it will be a problem to play 10 years.
Summary: In fact, two years is neither too short nor too short, and there are many suitable games, most of which are sandbox, high degree of freedom and so on. Of course, you can also choose the game masterpieces that you are interested in, such as My World, Starcraft, Warcraft, Civilization Series that I didn't mention, or games that can get various MODs. You can play for a long time, you can freely find what you like, you can innovate, and you can definitely complete two years of solitude, psychologically.