Rusty's Retirement is an idle farming sim from solo developer Mister Morris Games, released on 26 April 2024. Its trick is the layout: the farm docks to the bottom of your screen as a thin strip so it runs beside a browser, a code editor or a stream, and a vertical side-screen mode and a slower Focus Mode exist for people who want it even less distracting. You play a robot named Rusty who plants crops, converts them into biofuel, turns biofuel into spare parts and spends those parts on more land, more bots and more robot neighbours. There are 71 achievements and a Twitch integration that lets chat run the farm, and the game sits at 97 percent positive on Steam.
Boss fights are where Rusty's Retirement tests everything you've learned. This guide covers strategies for bosses across all areas, organized by progression order. For general combat techniques, see our combat guide.
Boss Difficulty Overview
| Area | Difficulty | Recommended Build | Key Equipment |
|---|---|---|---|
| Rusty's House | Easy | Echo | Harvest Bot |
| Biofuel Converter | Moderate | Echo | Harvest Bot |
| Echo's Workshop | Hard | Haiku | Water Bot |
| Slate's Barn | Very Hard | Haiku | Water Bot |
| Bulb Hives | Extreme | Haiku | Water Bot |
Rusty's House Bosses
Area difficulty: Easy Recommended level: Present from the first minute Recommended build: Echo with Harvest Bot
Strategy
The first bosses teach core combat mechanics. Focus on learning patterns rather than dealing damage. The window is a strip pinned to the bottom of the screen rather than a normal game window, so it stays visible while you work in something else. This is your primary tool here.
Key tips:
- Don't rush. Learn the attack patterns first.
- Use Bottom bar farm that shares your desktop to create safe windows.
- Harvest Bot is enough to handle everything here.
Biofuel Converter Bosses
Area difficulty: Moderate Recommended level: First 20 minutes Recommended build: Echo with Harvest Bot
Strategy
Early game bosses test your understanding of Biofuel converters and spare parts. Players who skipped learning this mechanic will hit a wall here.
Key tips:
- Biofuel converters and spare parts is critical for these fights.
- Farm Harvest Bot upgrades if you're struggling.
- Consider switching to Echo if your current setup isn't working.
Echo's Workshop Bosses
Area difficulty: Hard Recommended level: Early to mid, after Haiku's House Recommended build: Haiku with Water Bot
Strategy
Mid-game bosses are the major skill check. They combine multiple mechanics and punish players who rely on a single strategy.
Key tips:
- You need both Bottom bar farm that shares your desktop and Seven bot types running the farm mastery.
- Water Bot makes a significant difference. Get it before attempting these.
- See our combat guide for advanced techniques.
Slate's Barn Bosses
Area difficulty: Very Hard Recommended level: Late, once spare parts run past 20,000 Recommended build: Haiku with Water Bot
Strategy
Late-game bosses are serious challenges. Build optimization matters as much as mechanical skill.
Key tips:
- Make sure your build is fully optimized.
- Water Bot at max upgrade is recommended.
- Study each boss's attack patterns. Most have 2-3 phases.
Bulb Hives Bosses
Area difficulty: Extreme Recommended level: Mid to late Recommended build: Haiku with Water Bot
Strategy
Endgame bosses are the ultimate test. They require mastery of all combat systems and an optimized build.
Key tips:
- Top-tier build with best-in-slot gear is mandatory.
- Master every mechanic. See our combat guide.
- These fights reward patience and pattern recognition above all else.
General Boss Tips
- Learn before you fight: Spend your first attempt observing attack patterns. Don't try to win on attempt one.
- Match your build: Some bosses favor certain builds over others. Don't be afraid to switch.
- Upgrade your equipment: A max-upgraded Water Bot trivializes fights that seem impossible with weaker gear.
- Use Bottom bar farm that shares your desktop: The core combat mechanic is your best defensive tool in every boss fight.
- Check the walkthrough: Our walkthrough tells you when you're ready for each boss.
More Rusty's Retirement Guides
- Rusty's Retirement Rusty's Retirement Overview
- Rusty's Retirement Best Builds
- Rusty's Retirement Tier List
- Rusty's Retirement Walkthrough
- Rusty's Retirement Beginner's Guide
- Rusty's Retirement Tips & Tricks
- Rusty's Retirement Weapons Guide
- Rusty's Retirement Combat Guide
- Rusty's Retirement Maps & Locations
- Rusty's Retirement Crafting Guide
- Rusty's Retirement Classes & Characters
Similar Games
If you enjoy Rusty's Retirement, check out these related guides:
- Stardew Valley Boss Guide: simulation game with similar mechanics
- Satisfactory Boss Guide: simulation game with similar mechanics
- The Sims 4 Boss Guide: simulation game with similar mechanics
