This jam is now over. It ran from 2022-04-30 04:00:00 to 2022-05-30 03:59:59. View 9 entries

Everything leads to this moment. The moment you’ve been hoping for, the moment you’ve been dreading. It’s time to step into the arena and face the big bad boss.

Make a Boss Battle inspired by your favorite 2D games. Think of games like Legend of Zelda, Titan Souls and Binding of Issac. One player, one big bad enemy, limitless possibilities. 

All games must be made using DragonRuby Game Toolkit.

As always, this jam will be relaxed and beginner-friendly while also offering a challenge to more experienced developers.

Sample games will be available which you can use to get started with your own game.

This is a non-competitive jam. You may submit as many games as you like. Working in teams is strongly encouraged.


DragonRuby is a 2D game engine that’s super easy to get to grips with but powerful enough to make professional strength games. It uses the Ruby programming language and it can build games for Windows, Mac, Linux, consoles, and phones! 

Sample Games

DragonRuby creator Amir Rajan created a simple Boss Battle sample game. You can use this beginner-friendly sample to get started with your own game. It is included in the samples folder when you download DragonRuby. 

To use the sample:

  1. Download DragonRuby Game Toolkit
  2. Unzip the file and look inside for this folder: samples/99_genre_boss_battle
  3. Copy the contents of the 99_genre_boss_battle folder into the mygame folder, letting it overwrite any files that are already there
  4. Run the DragonRuby executable file (DragonRuby on Mac/Linux, DragonRuby.exe on Windows) to launch the game
  5. Look in the mygame/app folder and open the file main.rb in a text editor or code editor (such as Visual Studio Code)
  6. Change the code and save the file to see changes in the running game
  7. For help with DragonRuby, visit the DragonRuby Discord:


  • A Boss Battle sample game is included with DragonRuby (see above)
  • The DragonRuby Discord is friendly, supportive and incredibly helpful
  • For inspiration, here are some are examples of the kind of Boss Battles you could build from the sample games
  • Follow @groteskly on Twitter for news and updates about the jam.

Keep it Simple

It’s easy to bite off more than you can chew. Increase your chances of finishing your game by keeping it as simple as you can. To limit the scope of your game, we suggest the following:

  • Limit the game to a single screen (no scrolling).
  • Limit the number of inputs the player can use to directions and one other key or button.
  • Above all, remember to Keep it Fun and Stupid (KIFAS)!

If you finish your game early, use the extra time to add features and polish or go ahead and make a second game.


  • Be kind to each other. Be respectful and tolerant towards all other participants.
  • Don't include any assets (e.g. images and sounds) that you do not have a legal right to use.
  • Games must be developed with DragonRuby Game Toolkit.
  • Games containing mature themes or material that is not suitable for young audiences should be very clearly marked.
  • Try to play as many jam submissions as you can and leave constructive feedback.


Q: I don't like coding but I'm good with graphics, sound, writing or some other valuable skill. Can I join?

A: Absolutely. We encourage participants to work with a team. Come to the DragonRuby Discord and ask if anyone wants to team up. The same goes for coders who want to team up with other creative types.

Q: Can I start working on my game before the jam starts?

A: Yes! Start whenever you like.

Q: What if I've never made a game before?

A: This is a beginner-friendly jam. The simple sample game is designed to be used as an easy starting point for everyone, regardless of their experience.

Q: Can I submit an unfinished game?

A: Yes but please submit it near the end of the jam. Do not submit non-functional games.


This jam is organized by members of the DragonRuby community, with the help and permission of DragonRuby. Check out our other jams: TeenyTiny DragonRuby MiniGameJam and DragonRuby Classics Jam.

Original artwork © UG (limited liability) & Co. KG. Used by permission.


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A Tale of Honour, Justice and Blunderbusses
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A hot morning cup just might turn this around...
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A very little unfinished "game" for DragonRuby Boss Battle Jam
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Escape a subterranean facility
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Boss battle against the Sun
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A basic boss battle with DragonRuby source code for the Boss Battle jam
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Made for DragonRuby Boss Battle Jam
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