Undergarf is where the characters of Garfield and Undertale combine. It's a carefree place, free of war and strife. Free of mondays! You play as Nermal, who stumbles upon this world and challenges Sansfield, the fusion of Sans and Garfield, to the ultimate duel.


Bad Monday Simulator has it's own category on Twitch! Also:

monD monKEKW monPray monRIP monS 
monTalk monLaugh monZZZ monSadge monLasagna

Bad Monday Simulator is drawn by myself, Lumpy.
programmed by Spasco
and has music by Polarial
Inspired by the works of Toby Fox
Inspired by the works of the immaculate Jim Davis.

Additional music used:
【無料フリーBGM】パイプオルガンの明るく荘厳な曲「Pray Organ3」 https://peritune.com/blog/2020/12/07/pray_organ3/
【無料フリーBGM】パイプオルガンの悲しいレクイエム「Pray_Organ2」 https://peritune.com/blog/2019/11/10/pray_organ2/

  • FAQ: I'm not hearing any music! How can I fix it? A: Try reopening your web browser.
  • FAQ: Will the soundtrack be releasing? A: YES. It'll be on YouTube soon.
  • FAQ: How many endings are there? A: 6. 2 for Normal Mode. 2 for Hard Mode. 2 for Monday Mode.
  • FAQ: Monday Mode seems impossible. A: That's not a question. And yea, it is. I can't beat the game on Monday, that's for sure.
  • TIP: Praying sometimes summons a rare Pasta Fairy! Try doing some PRAYS early, and if you're lucky, maybe you can stockpile some healing items!
  • TIP: Sansfield inflicts poison/karma damage when he hits you. This is displayed as purple health and slowly ticks down. Items cure poison/karma and THEN heal you! So healing quickly means you can recover more hp!
  • TIP: When Sansfield is sleeping, he prefers to not be disturbed.

Feel free to use this artwork from the game for YouTube Thumbnails/articles, etc.

Latest update is live!
-WASD controls added.
-all videos are now unlocked!
-some more bugfixes

Rated 5.0 out of 5 stars
AuthorsLumpy, Spasco
GenreRole Playing
Made withGameMaker: Studio
TagsBoss battle, Fangame, Indie, lumpy, Parody, Pixel Art, Singleplayer, Undertale, video


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Viewing most recent comments 1 to 40 of 175 · Next page · Last page

has anyone beat monday mode here

Can u pls give me a tip on the lasers they too hard lol

lol I cant even beat it on normal mode

Great now just add a good game

anyone have tips for the Z attack when sansfield is sleeping?

just tap the up/ down button or something

You should add the Karma sign next to the hp

Man, imgaine if this was made to a full game.


How do you go in full screen?

I don't think there is full screen. What I do is press f11 then just zoom into the game with the touchpad (if you have one)

yo wheres his pipe tho?

a terrible blight, monday

Thanks for blessing us with this

pro tip, move the soul to the bottom left corner during the odie bone attack

amazing game

for undertale garfield this isnt bad at all

I literally created an account to play this, and it still does not work. Can anyone please explain why this is happening?

oh fuck


I am determined as the little shit nermal i am to NO HIT THIS as im a little sussy 12 boi that will complete the task because i have nothing else to do with my pathetic life

If i can get the sound working


really good game!


So this is what hell is like, except this is worse

(1 edit) (+2)

how do i make this full screen?


I love undertale and this was awesome!!


WOw this was amazing


yay i punched my monitor bc i got mad


This is the definition of impossible.

(1 edit) (+1)

i [[harmfully respect]] your [[humane]] opinion even though i have a [[opposite]] opinion  

HEY THERE LUMPY YOU LITTLE [[slime]] HAVE YOU HEA RD OF THESE [[amazing deals 1997]]? THEN WHY DONT YOU MAKE A [[hyperlink blocked]] ABOUT A [[lonely heart]] LIKE ME? SINCERE:LY SPAMTON G SPAMTon 


i think spamton means you have to pay him every time you pray and get big shot

what my comment meant is that lumpy should make a game about spamton


i wish there was a 1/100000 chance that the garfield gun attack is replaced with kitchen gun, if you dont understand this will make you understand


i have advice for if your trying monday mode (inhales) just give up, the creator of the game LITERALY SAID HE CANT BEAT MONDAY MODE AND THAT ITS IMPOSSIBLE

There are multiple videos and i saw pepole stream beating monday mode, its possible but extremely hard

Bruh, I've already no hit-ed every move. At this point I'm just throwing in runs until the stars line up and I dodge everything in the same attempt.

hey you stole my username lol

lol sorry. It's a pretty generic name, but I've been using it for like 7 years so I've claimed it in a bunch of websites already.


i just came up with it on the login page in like 2020 to find dumb games soooooooo


aaa thess is so afecive!!!!!!

Deleted 75 days ago

why are you trying to rickroll us, and how did you think that would work, i mean it literally has rick astley on the front.

im not a crap eating idiot


I already know about the rickroll. i saw it on a short

cool game especially cuz i played undertale

if you dont click the game fast enoth on the loding screen it gliches out a lot

i can´t download this thing, so everything is just like the size of a pixel and is impossible to beat that XD


I pressed run game, it isn't working, do I have to wait for a loading screen.





thats not a glich kido.

its not a glitch, you restart when you die, yeah it is hard but thats the point!

(1 edit) (-2)

Bruh i got back to phase 1 when i was fighting phase 2, can you fix that pls when you die in current phase you restart at current phase?


I cant survive the gaster blaster attack, PLS CHANGE THAT ATTACK AND MAKE IT EASIER


u are just bad lol


I want to download this!! please this game is so C O O L!!


MAKE IT FOR DOWNLOAD PLS, btw the game is amazing

Viewing most recent comments 1 to 40 of 175 · Next page · Last page