Recommendations: Creative Difficulty Mods
A list of mods that make the game more difficult in more interesting ways than just increasing or decreasing stats. Some of these have not been tested in 1.5, so check the comments and be careful if installing them into an existing game.
Farming
Watering Grants Experience And Crops Can Wither
Author: Goldenrevolver
Watering Grants Experience And Crops Can Wither, as the name suggests, adds the possibility for crops to wither and die if not watered either by rain or by the player. You can configure how many days it'll take without watering before they'll die.
Animals Die - Old Age - Hunger - Illness
Author: Goldenrevolver
Animals Die - Old Age - Hunger - Illness adds the possibility that farm animals can die by various means, both preventable and unpreventable. Has additional functionality if Animals Need Water is also installed.
Animals Need Water
Author: GZhynko
Animals Need Water adds functionality to the water troughs in barns and coops so that animals will lose friendship if they aren't provided with fresh water each day.
Balanced Valley
Author: o0MrPro
Balanced Valley includes different balance modes; in particular, the "deadline mode" changes crops so that the player must plant only on the first day of the season and harvest on the last day of the season, and removes crop regrowth. (note: works but requires Shop Tile Framework).
Note: The mod's last updated was 2022. It is still playable in 1.6, but has some bugs. Please see mod post discussion for further information.
Seed Shop Progression Mod
Author: 9br3
Seed Shop Progression Mod changes Pierre's shop menu so that he only has a small selection of seeds in Year 1 and improves his stock over time.
Farm Fresh Produce
Author: zombifier'
Farm Fresh Produce rewards you for selling items the same day as you harvest, instead of hoarding them, and sets seasonal goals that encourage a variety of planting over minmaxing.
Friendships
Gift Decline
Author: desto / JustToDownloadThings
Gift Decline changes the gifting system so that townspeople will like gifts less if they are given the same thing too often, requiring the player to be creative in what you gift people.
Enhanced Relationships
Author: Mizzion
Enhanced Relationships (Nexus) / (ModDrop) makes gaining friendship more difficult by increasing the friendship decay rate and adding a loss of friendship points if you don't give someone a gift on their birthday.
Friendship Decay
Author: stardemod
https://www.nexusmods.com/stardewvalley/mods/21323 Friendship Decay triples friendship decay and removes decay stopping at max hearts.
Food
Allergies
Author: BarleyZP
BarleyZP's Allergies makes you allergic to certain foods, depending on which allergens you choose. Many custom food mods are tagged with allergens for compatibility!
The Love of Cooking
Author: blueberry
The Love of Cooking overhauls the cooking system in many regards, but also adds the frying pan as a new tool that needs to be upgraded in order to access higher-level recipes, makes food heal over time instead of instantaneously, and adds the chance of burning food at low skill levels.
Spice of Life
Author: KarratKake
Spice of Life reduces stamina gains from foods eaten too frequently, so that you have to vary your diet in order to gain maximum benefits.
Farm Maps
Small Beach Farm
Author: Pathoschild
Small Beach Farm adds a tiny beach map with a river mouth where both ocean and river fish can be caught.
Tiny Beach Farm for 1.6
Author: Dximafe and puchiyang
Tiny Beach Farm has a small area for farming and no greenhouse.
Micro Farm
Author: StarMoon7
Micro Farm is juuuust large enough for a barn, coop, fish pond and greenhouse, plus a small plot for crops.
Permafrost Farm
Author: rkpiotr
Permafrost Farm is a small farm in perpetual winter, so only winter crops will grow, animals will not go outside, and grass won't grow.
An Utterly Atrocious Farm
Author: deleted203499311
An Utterly Atrocious Farm is mostly made of twisted paths to get anywhere, including your one tile of farmland. Have fun!
Combat
Custom Death Penalty Plus
Author: MightyAmondee
Custom Death Penalty Plus (Nexus) / (ModDrop) allows for customisation of the penalty of dying in the mines, Skull Cavern, or volcano, including the option for friendship loss with Harvey and Maru, applying a random debuff, and adding more potential places to wake up other than the clinic or the mines.
Boss Battles
Author: Nature
Boss Battles adds fights in the mines against several powerful monsters.
Personal
Cacti Hurt You
Author: CatCattyCat
Cacti Hurt You (Nexus) / (ModDrop) changes cacti so that you lose health if you run into or interact with one.
Starksouls
Author: FenrirAsonda
Starksouls makes the farmer's health and stamina keep the same values from the day's end in the next day rather than returning to full. The amount of health/stamina recovered is configurable, as is the amount of health/stamina recovered after dying.
Stardew Survival Project
Author: FenrirAsonda
Stardew Survival Project adds various realism mechanics to Stardew Valley such as thirst, hunger, body temperature, and a HP rework.
Other
Hardew Valley (Hard Mode - Plan smart - Risk it all - QoL)
Author: Juanpa98ar
Hardew Valley has options to change the majority of statistics to make the game more difficult.
Challenging Community Center Bundles
Author: Alvadea & Jaksha6472
Challenging Community Center Bundles (Nexus) / (ModDrop) edits the Community Center bundles for increased challenge.
Ferngill Revenue Service - A Taxes and Bills Mod
Author: KarratKake
Ferngill Revenue Service adds a tax system that taxes the player based on your income, your water bill (calculated from the number of sprinklers), and your electricity bill (calculated from the size of your farmhouse, the number of farm buildings, and the number of machines).
Crowcalypse
Author: stardemod
Crowcalypse adds a daily horde of crows who steal anything not nailed down.
Custom Dungeon Floors Updated
Author: aedenthorn and ADumbBagel
Custom Dungeon Floors Updated makes it possible to configure many aspects of the mines and Skull Caverns, including how often monster floors spawn, how many monsters will be present on each dungeon floor, and how many gems, nodes and ores will spawn.
More Random Edition (Randomizer)
Author: Chikakoo, doomdonuts & Tooshi
More Random Edition (Randomizer) randomises many elements of the game, including randomised bundle sets, crafting recipes, crops, item trees, and more.
Restauranteer Continued
Author: aedenthorn and CyanFire
Restauranteer Continued lets you work part-time in the Stardrop Saloon as a short-order cook, fulfilling patron food orders for coins, friendship points, and cooking proficiency.
Project Danger Weather
Author: kath40
Project Danger Weather adds a variety of daily weather-related effects and debuffs.