Gameplay in Atomicrops is divided into levels of difficulty called Years. Before each run, the player can select which year they would like to play by interacting with a sundial at the Farmhouse. There are 10 years in Atomicrops currently. Each consecutive year is unlocked by beating the prior year and the difficulty increases with each year. Some years may unlock additional features the first time they are completed.
Year 1 is the default, and starts off every player's first experience. It can be considered the easiest year. Beating year one unlocks a new spouse, Waterchris, as well as the achievement Year One Lotus.
Year 2 will unlock a new playable character, Robusta.
Year 3 will unlock a new NPC, The Gamble Trader.
Year 4 will unlock a new playable character, Thyme.
Year 5 will unlock the achievement Demi-Decade Orchid