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Watch trailer on Steam ↗S.E.M.I. – Side Effects May Include...
Two Horn Unicorn · Published by Two Horn Unicorn
Very Positive — 86% positive (113 reviews) · 9 achievements
Last updated 28 Sept 2026
S.E.M.I. is a single-player and co-op action platformer with puzzle elements. Play as patients of an unusual clinic, take experimental drugs, interfere with each other, and be ready for chaos and unpredictable side effects!
£6.69
Lowest price we've ever recorded
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Price history
Action, Indie · 2026 · More £5 - £15 games
Navigate through a clinic where taking pills leads to bizarre transformations and co-op mayhem. Side Effects May Include... challenges you to solve puzzles and survive the unexpected in this unique action adventure.
About this game
S.E.M.I. is a cooperative online game about escaping from a special clinic. Here, you and up to 3 of your brainless loyal friends play as patients, fighting staff and other patients while stumbling into all sorts of unexpected situations. Brawls, side-effect pills, and brutal platforming will absolutely challenge your clumsy friends’ hands sense of teamwork. Expect obstacles, puzzles, deadly traps, and rooms where a single wrong move can knock out the entire squad.
Communicate in voice chat and arrange sabotage help your friends pass through rooms, get out of traps and fight with opponents! In your arsenal: close combat, physics, amazing abilities and ... imagination!
Take pills and get abilities:
Bipolar force is an invulnerable monster, then a helpless rag!
Laser astigmatism — two sights, one laser… Where will he shoot?
Stendhal syndrome — are you looking at a painting? Now you're hysterical and destroying everything around you!
Alice's syndrome is either tiny or gigantic — have time to adjust!
Madness is near! You and your friends can go crazy and start running, jumping and fighting, and your abilities will become uncontrollable. Do you want to take back control? Take the pills :)
Locations are randomly generated from rooms with changing gravity, traps, moving walls, and other "pleasant" surprises.
After a successful escape, you will receive a medical report: "The patient was stable until he started hitting the guards with a bottle. Diagnosis: Overmotivation" or something worse!
Unlock new costumes and decorations. Let each new escape be more stylish than the previous one!
Will you and your friends be able to escape... or at least not go crazy?
Welcome to the mental hospital! Here, your abilities are a lottery, and your friends can be the most dangerous opponents!
System Requirements
Will my PC run this? →Minimum
- Requires a 64-bit processor and operating system
- OS: Windows 10
- Processor: Intel Core i5 series or Ryzen series
- Memory: 8 GB RAM
- Graphics: GTX 960 or AMD R9 290
- DirectX: Version 11
- Storage: 3 GB available space
Recommended
- Requires a 64-bit processor and operating system
- OS: Windows 11
- Processor: Intel Core i7 series or Ryzen series
- Memory: 8 GB RAM
- Graphics: GTX 1660 or RX6600
- DirectX: Version 12
- Storage: 3 GB available space
Supported Languages
Latest news
Patch NotesOfficial
New Patch Is Live!
We’ve added something many of you were waiting for!Steam AchievementsAchievements are now available — for escapes, failures, and questionable decisions.Steam CollectiblesNow available:8 trading cards6 badges5 emoticons3 profile backgroundsWhat’s next?We’ll keep that a secret for now 👀Stay tuned.Read full article on Community Announcements (steamworks)AnnouncementsOfficial
S.E.M.I. is officially released!
S.E.M.I. — Side Effects May Include is now fully released!Patients, we’ve officially left Early Access — S.E.M.I. is now available in its full release version on Steam.During Early Access, we put a lot of work into expanding content, improving core mechanics, optimizing performance, and refining the game based on community feedback. The release version is the most complete, stable, and polished S.E.M.I. experience to date.What’s new in the full release?Expanded Diagnosis SystemAn expanded version of the diagnosis system has been introduced. Diagnoses can now be unlocked by progressing through Escape Mode, adding more depth to progression and replayability.New Story Mode ContentStage 3 has been added to Story Mode, featuring:12 unique new levels2 new puzzle-focused levels1 final Crazy RoomNew Enemies2 new elite enemy variants2 brand-new mechanical enemies that add new combat and tactical challengesNew EmotionsThe set of player emotions has been expanded, making interactions even more expressive and chaotic.Reworked Voice ChatThe in-game voice chat has been fully reworked. Communication is now stable, convenient, and free of technical issues.Performance OptimizationThe game has been optimized to run on lower-end systems, making the escape from the clinic accessible to more players.Balance ChangesEnemies and the in-game economy have been rebalanced for a smoother, fairer, and more enjoyable experience.Visual & Audio ImprovementsEnvironmental visuals and sound design have been upgraded to enhance atmosphere and moment-to-moment impact.Bug FixesNumerous minor bugs have been fixed, improving overall stability.Thank you to everyone who supported us during Early Access ❤️S.E.M.I. — Side Effects May Include is now available in its full release version.The game is available now on Steam!See you in the clinic.Side effects guaranteed. 💊🏥Read full article on Community Announcements (SEMIlover)Patch NotesOfficial
Last Early Access update
Patients, attention! 🚨We have some very important news!On January 23, Side Effects May Include is officially launching into FULL RELEASE!A huge thank you to everyone who took part in Early Access and shared their feedback — you truly helped make the game better ❤️And today, we’re releasing a patch that adds an exclusive Early Access skin.Any player who has completed at least one level will be able to purchase it in the wardrobe.You have 10 days to claim it — after the full release on January 23, this skin will no longer be available.So if you’ve been keeping an eye on the game or putting off your purchase, this is your sign to grab it now and permanently unlock an exclusive reward for Early Access players!Read full article on Community Announcements (steamworks)AnnouncementsOfficial
Let's escape to 2026!
Happy New Year, dear patients! May your escapes from the clinic be chaotic, fun, and (ideally) successful, and may your loyal, slightly brainless friends never drop you into traps at the most inopportune moment... Or at least let them do it epically - you'll have something to remember. Thank you for going crazy with us and making this year truly unforgettable! May the next one bring even more broken teamplay, unexpected abilities, and epic escapes. See you in the ward! {STEAM_CLAN_IMAGE}/45747930/b9ce34cf68ed2319e922e52e587f3a3a68faaca7.png Don't forget to follow the news and updates on our social media: X Discord TikTok YouTubeRead full article on Community Announcements (wolfelee)AnnouncementsOfficial
Observation Journal
Patients, Attention! It's customary to sum up the results at the end of the year - and we are no exception. We want to share some fun stats with you about what you've managed to achieve in the first month since the game's Early Access release. A Few Numbers This month you have: Successfully escaped the mental hospital 3,857 times and received your diagnoses Swallowed over 12,500 pills Picked up around 364,000 pieces of candy Insane results - keep it up! {STEAM_CLAN_IMAGE}/45747930/9d3d7f52328b76d64bbfa697638c0b6df57b35d4.gif What's Next? Right now, the entire team's resources are focused on preparing the project for the full release in January. The main focus is on stabilization, refining mechanics, balancing, and polishing the existing content. From our immediate plans: Adding a third run stage, which will consist of three sub-stages Expanding the game content and further refining current systems based on your feedback Thank you to everyone who is playing, sharing impressions and ideas, and sending bug reports - this directly impacts the quality of the game and the speed of its development. Don't forget to follow the news and updates on our social media - there's still a lot of interesting things ahead. X Discord TikTok YouTubeRead full article on Community Announcements (wolfelee)
