The player takes on the role of a young farmer, default "Pete", whose parents left him in charge of his late grandfather's farm. Over a two-and-a-half year time period, the player must develop the decrepit, weed-choked farm into a money-maker, and if possible, get married and have children.
At the game's end, the player is evaluated on a number of factors to determine his success or failure. The player's farm is evaluated by the player's father at the middle of the third year.
There are three different areas the player can go to: his farm and its buildings, the local town, Neighbor Town and its houses and shops, and the local mountain forest, where the carpenter lives. Further north of the forest is the mountain's peak.
The house can be upgraded twice. Additionally, wood can be used to construct fences around the crop areas. While rain releases the player from having to water crops by hand, it usually damages the fence. After winter, no matter how well the player takes care of the land, much of the cultivated land and fence is destroyed.
After dark, the only business in town the player can access is the bar, where a number of game characters gather to drink and talk.
The player progresses by:
- Preparing the fields. Before any crops can be planted, numerous weeds, rocks, and tree stumps must be cleared from the ground. Then the player must till the soil before it can be cultivated.
- Planting crops (turnip, potato, tomato and corn) on cultivated land, watering it, then harvesting the vegetables and selling them for profit.
- Raising livestock. In this version of Harvest Moon, only chicken and cows, which produce eggs and milk are available. By planting grass and harvesting it into hay, the player can feed these animals.
- Enlarging the farmhouse. By using the axe to gather wood, the player can chop up enough tree stumps to build a larger house. This requires money as well as wood.
- Getting married. Five girls in town are potential brides. By giving gifts, visiting on the correct days, and fulfilling specific requirements for each girl, the player can get married and have his wife move onto the farm with him.
- Having children. Within the game's time frame, it is possible for the player's wife to have two babies. One child will develop into a toddler given enough time.
Each year is divided into four seasons of thirty days each, and the player only has a set amount of time each day before it becomes dark. However, the clock stops at 6 p.m.; unlike in later Harvest Moon games, the player can effectively stay outside as long as he wants without penalty, as long as he doesn't run out of energy.
- Crops, eggs and milk can all be placed in collection boxes; at 5 p.m. every day, a shipper will come by and pick these items up; the player receives money the next morning. The player can also gather herbs and wild fruit in the forest for sale. A small pond allows the player to go fishing as well.
- The player can only farm vegetables during the spring and summer. During fall, the only thing that grows is the grass used for fodder; in winter, nothing grows.
At the beginning of the game, the player adopts a dog, Koro, but the dog requires no special care, nor does it contribute to the game except for barking to warn the player that the farm's fence requires fixing. In the winter of the first year, the player also adopts a horse, which proves helpful when harvesting crops.
All cows are purchased from a livestock dealer in town, as is at least one chicken. The barn and hen house are capable of holding up to twelve of its respective animals each. Additional chickens can be hatched by placing an egg in an incubator rather than selling it.
- Cows, when first purchased (or born), require time to grow before they can be milked; afterwards, they grow larger and produce larger quantities of milk. Both fully-developed chickens and cows can be sold at a profit.
- Animals must be fed once a day to keep producing. Cows must be continually talked to, brushed, and milked to retain their health - unlike the chickens, if a cow is not fed for a day, it may become sick and possibly die.
- The only way a chicken can die is if it is left outside and is blown away in a storm or eaten by wild wolves.
The player starts with basic tools, such as a watering can, axe, hammer, hoe, and others. All these tools can be upgraded if the player completes certain side quests (although the watering can's improvement must be purchased).
There are a number of events (some scheduled, some not) that break up the gameplay:
- Festivals to celebrate an event.
- Storms happen during the summer season. If this happens, the player loses a day of work while barricaded in the farmhouse, and many of the crops, large sections of the fence, and even cultivated land itself will be destroyed.
- Earthquakes. While less common (and unpredictable), these have some of the same effects as the hurricane.
Some of the game's special events require one of the above disasters to allow the player to access it.
At random points in the game, the player has the opportunity to take part in side quests that provide benefits.
After an earthquake or lightning strike, for example, the player can meet the "Harvest Sprites" who live in tunnels under the farm. They can also gain access to a pond where the "Harvest Goddess" lives. Doing these things allows the character to upgrade his tools without paying money.
There are minor secrets hidden throughout the game, mainly related to "power berries," which increase the player's overall energy. These range from digging in a particular place to planting a rare flower on a certain day of the year. The farm has a flower garden on its north side; for each of the twelve berries the player finds and eats, a special flower blooms.
A wandering peddler makes appearances on certain festivals, and on Sundays. The peddler sells the "blue feather" required to propose to a girl, as well as other rare items. There is also a hawker who sells and, if the player tries to sell livestock on certain day, is willing to trade them for unusual items.
As mentioned above, there are five unmarried young women living in town who may be married. To get married to a girl, you must propose to them with a blue feather. They are:
- Ann - A tomboy and daughter of the tool store owner, she works as an inventor, though not a terribly successful one.
- Ellen - The daughter of the cafe owners, she enjoys animals. While her mother tends the restaurant, her father is the town drunk.
- Eve - A waitress at the local bar, she tends tables nearly every night. Though flirtatious and outgoing, she has abandonment issues, as she grew up without her parents.
- Maria - The mayor's daughter, Maria spends her time reading and tending the grounds of the local church, where she plays the organ.
- Nina - The daughter of the flower shop owner, she enjoys nature, and of course, flowers.
Each girl has her own tastes and preferences. All have their own diaries, in which the player can regularly check to see how attracted the girl is to him.
After marriage, aside from their hair color and particular phrases, they tend to look alike, and the player's activities are severely curtailed - he is expected to come home by a particular time, and not doing so may result in the wife leaving the player temporarily (it is not possible to divorce permanently).
If the player arrives home at the proper time to go to bed with his wife, she will eventually get pregnant, and the baby is later delivered in the farmhouse.
- In the censored version of the game released in North America, all alcoholic beverages are referred to as "juice," even though anyone who drinks said "juice" clearly becomes intoxicated.
- While many elements of the game were Westernized for its American release, some Japanese references were overlooked. For example, although the church is presented as presumably "Christian-like" due to the cross, townspeople sometimes discuss the church and its religion in Shinto terms, such as referring to the existence of both a "god of the harvest" and a "god of business."
- This in term does not label any religion in the series, but draws influence from them.
- In the Japanese version, the title is made from planks of wood nailed together. For all other releases, this was replaced with a 3D-rendered sign.
- Fences are rendered superfluous and outright useless in the first iteration of the series; broken fences attract wild dogs, than keep them out.