A downloadable game for Windows

Atom OI is an experimental series of turn-based battles in RPG Maker 2000. Its chief purpose is to explore short-term status ailments as a means of providing defensive support to vulnerable party members by preventing damage. Key features include:

5 tense, tactical battles. A concise experience leaning toward short- and medium-term strategy, Atom OI lasts only long enough to introduce and explore core concepts and aims to wrap up before fatigue sets in.

- Thoughtful defensive play. Every class has a role to play in the party's defense, but the Disruptor makes protection her specialty. What's the biggest source of danger in the fight? How can you best leverage her powers to keep the danger under control? What happens when you can't? These are some of the main questions I wanted to explore with Atom OI's party.

- Also, this one's tough! The value of defensive options is more obvious when death is close at hand, so enemies in Atom OI hit fast and hard. But you have all the tools you need to survive, so take your time, save often, and don't be shy about the "retry battle with full HP/MP" option.

I'm interested in hearing about your experience with this system! I invite you to share your thoughts and feelings in the comments below.

Estimated play time: 60+ minutes


Escape/XCancel, pause combat messages
F4Toggle windowed/fullscreen (windowed mode recommended)
F5Toggle resolution


MusicNARF (narfnra.bandcamp.com)
TestingMoxSully, S.K.
Special thanksKA·IN WORKS, and the Vextro community
Other art & sound assetsRPGMaker 2000 RTP
Rated 5.0 out of 5 stars
GenreRole Playing
TagsExperimental, RPG Maker, Short, Turn-Based Combat

Install instructions

Extract the game files from the .rar or .zip archive using your favorite extraction software, then run "RPG_RT.exe" to play.


Atom OI (RAR) 32 MB
Atom OI (ZIP) 34 MB


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I highly liked this!

the begining was pretty frustrating, had to try the first level or two for a few times until it sort of clicked and I finished the rest in a seating. this bashing repeatedly against the wall until I get it and then I can manage de enemies pretty smoothly I guess is how people's experiences with soulslike's are?? although I never played those. it was cool to experience that here.

I like that the difference between doing it wrong and right is getting wrecked or managing the situation pretty well. I much prefer that style of combat, of fully countering big threats, to slowly chipping off damage.

it was really cool to have this very dense compact experience of getting to know this system and the dynamic between the characters and going from a very naive and reluctant play style to feeling I could actually control the situation.

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Cool game!

I wrote some mechanics feedback in a pastebin: https://pastebin.com/0Dc61Qw9  (Not posting them inline this comment because I realized they could spoil the mechanical learning for anyone who hasn't played it yet.) 

Have you played Etrian Odyssey 2 by any chance?  This reminded me a bit of it, since that game has a really cool debuff class: https://etrian.fandom.com/wiki/Hexer


that's some valuable feedback! thank you for playing both games and sharing your thoughts. i think you're right about the physical/magical split - i think it's kinda like the black mage problem where if one character can do it all, the complexity is collapsed to "just use the right one".  if i revisit the concept in a future game (and i'd like to) i'll have to do some things differently.

i haven't played any etrian odyssey games in earnest yet, but folks are always pointing me toward them, so it'll happen one of these days. i'll be curious to see how the hexer plays - i generally find "debuff specialist" as a class concept doesn't click with me,  but from what i know of EO, i trust the series to execute on it in an interesting way. i'll keep an eye out for it.

That was dope as hell!! Just a good punchy set of battles that explore some very good player verbs. I love how these games explore super-specialized character roles, I think that adds a lot to the rpg combat experience. 

The fullscreen feature is messed up and otherwise it's tiny. When I go into full screen, it doesn't go all the way and it gets very blurry.

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ah, if you press F5 you can switch between two resolutions. that should make the game fill the entire screen in fullscreen mode and make it not-tiny in windowed. (unfortunately i don't know any solution for the blurriness in fullscreen mode - that seems to be unavoidable for rpg maker 2000 games on modern OSes.)

thanks for the note!

that was really fun! figuring out which enemy to prioritise and stopping them from dealing enough damage to take out the team was sooo satisfying. one thing id say that sort of bothered me was that there was no indication when Magic Wall's effect was going to run out so it i had to just pray that it would still be up in future turns. 

overall, this game was sweet and short enough for me to enjoy the whole experience :)

thanks for the feedback, i'm honored that you liked it! i'll remember your words on magic wall the next time i make a status ailment like that.

word, looking forward to playing this one < 3