KENSEI is an upcoming RPG for the GameBoy built in GB Studio.

Head to the land of Izumo, where Samurai still practice their craft, and Demons still prowl the surface. You play as the Ronin, a samurai seeking to surpass the Four Sword Masters to claim the title of "Sword Saint" - to become Izumo's KENSEI.


  • An "Open World" story: seek the sword masters in any order, or not at all! Perhaps you are skilled enough to defeat the Evil plaguing Izumo from the start...
  • A deadly turn based battle system: you must learn your opponents moves and find their weaknesses to end battle swiftly. Any fight could be your last if you are reckless.
  • A Rogue-Lite journey: you must conserve your HP & SP - to save your game in KENSEI, you must please the Kami with donations to their shrines.
  • Multiple skills to learn: challenge the Sword Masters to learn their hidden techniques, or learn optional skills to enhance your exploration of Izumo.
  • Crafting: collect items and manage your inventory space, and use resources to craft tools to aid you in battle.
  • Overworld combat: strike your foes with your Sword before they ambush you to gain an advantage in battle, or use Shurikens to eliminate them before they get the chance! No random encounters!
  • Stunning pixel art from Pixel Boy modified for the GameBoy by LazyDev, and gorgeous menu icons by Vector Pixel Star.
  • "Color Enhanced": KENSEI is playable in traditional DMG greens, but with color mode, Izumo evokes the feel of classic Samurai film/anime.
  • Secrets & Lore to discover: Inspired by Japanese folklore and classic Samurai media, KENSEI aims to please genre fans. 


  • D-PAD/Arrows/WASD: Walk, Navigate Menus
  • A/Z/J: Confirm
  • B/S/K: Cancel, Use Sword (Overworld Only)
  • Select / Shift: Throw Shuriken (Overworld Only)
  • Start / Enter: Pause Menu (Overworld Only)

Rated 4.8 out of 5 stars
(14 total ratings)
AuthorLazy Dev Games
GenreRole Playing
Tags16-bit, 2D, Black and White, Game Boy, Game Boy ROM, gb-studio, gbstudio, Ninja, samurai


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KENSEI v.D0.1 177 kB

Development log


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Such a short game but very good, I didn't understand some conrtrols though.

Glad you liked it! I'll need to come back and finish this sometime. I have some thoughts on how to revamp the battle system to make it clearer now that GB Studio 3.0 is out.


Amazing combat system!!

hope this is still being developed the battle sytem is so cool would be my favourite gameboy title ever if was completed.

Hi! This will eventually be finished! I ran into a major delay with this one over due to some PC issues (nothing was lost though!), then got distracted developing HAUNTING with Stranger, and then began to work on a game for GB Compo 21.

For KENSEI, the full mainland and all boss fights have been completed, so it'd just be a matter of powering through making more enemy types and then some cutscenes for the rest of it.

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Thanks for replying and sounds great can't wait to see the different bosses and enemy types and the story too! Look forward to hearing/seeing more about that game for gb compo 21 aswell.


Great stuff with the demo, one of the biggest scale GBStudio projects iv'e seen too. Lookin' forward to keppin' up with it.

Man, this is spectacular! I enjoyed playing it. 

The idea of making the enemy vulnerable and then hitting them when they do not expect it, which causes their death, is great. I'm afraid it could be the only way you would kill enemies, and therefore it may become the only "effective" method with no more joy of doing it. However, I absolutely loved this fatality cutscene.

The game seems very promising. 


Thanks! I agree that a big concern is that vulnerability becomes the only way to kill things. My goal for the full game is that vulnerability will be the *safest* way to kill, but as you find new abilities and upgrade your sword traditional damage could kill some enemies faster and not cost you precious SP. 

The demo island doesn’t really have enough enemy variety to show that, but once the main world is released I plan on enemies having different HP totals (and  resistance/immunity will be more frequent).

Appreciate the feedback!

the game really is awsome I will recommend it to people

Nice points on that! I'm glad my feedback was useful.

By the way, is there any way I can contact you? Maybe, via Twitter or Discord?

Discord is best - if you head to the GBStudio discord you can @LazyDev and we'll go from there!

i found a bug: after you beat the fire soul dude and the demon by the boat, walk out of the area where the battle took place, hold up to go back trough the red structure. hold up and left and the player sprite will change between different ingame sprites.

i also forgot to mention how great the game is. the story and combat are very nice. keep up the hard work ;D

You found it! A play tester reported the bug but I couldn’t replicate it. I’ll try what you did. That’s a very weird one lol.

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Just a quick update for you; the video was SUPER helpful. I've put in a fix for the  main game that should prevent this from happening on any screen, but this may actually be a bigger bug than in just my game (I may upload a new demo version eventually too)! Going to be submitting a bug report for GB Studio and this video is a great example. Appreciate it!

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i love this. i have been developing  a turn based like this myself and i have to say i am very impressed. you gave me some ideas for mine and keep up the good work and i can't wait for the official release

Oh nice! Shoot me a link when you've finished your game (here or on the discord/reddit) and I'd love to check it out!

do you have a game dev instagram?

I don't! 0% online presence outside of here, the gbstudio subreddit, and the discord. I should probably start something...

what is your discord?

I'm LazyDev on the GBStudio discord!

I enjoyed it! It felt somewhat like first mario and luigi idk why, and I love that game. Just a little note: I would remove the message "you got sth" after "you found sth". One message is enough.

Can't wait to see the full game! Good luck!

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Thanks! The original combat system actually had some timed inputs/QTE mechanics, so that's probably why it's got the Paper Mario / Mario & Luigi game feel. I took them out because they felt a little busy / janky timing. Maybe one day I'll do a combat system with those again.

Some behind the scenes info: The double messaging is because of the way the inventory is checked; it announces what you found in the chest, but if your bag is full you'll get a different second message. It's set up this way so you know what's in the chest if you come back to it, but I agree its a little repetitive. I could switch it up to something like "You found X" -> "You put X in your Bag" /  "You don't have enough space!"

Yeah, I think it would be perfect!


I am a HUGE fan of this project! Already it's looking so well polished and ironed out - I honestly felt like I was playing an official release when that boat hit the shore... Can't wait to see what this will become!!