An Undertale Interactive Fiction Fangame.

The demo for Undertale Penumbra is officially LIVE on Itchio and can be played here!

You press your hand against the dark glass, catching the awareness of a lone entity on the other side . . .

Demo Features

✧ Share a liminal space with a disembodied voice

✧ Create life a unique Vessel together

✧ Conduct his SOUL Questionnaire (please, it will be fun, he promises)

✧ ???

✧ There's a feral imp in the background for some reason

Hey friends, @poppymouth here! You can call me Poppy :) Just wanted to write a quick note to say I am SO excited to drop the demo for Undertale Penumbra and I hope you guys get a big ol' kick out of it. It was originally just a tech demo to try my hand on Twine but since then I have tumbled down the Undertale AU rabbit hole in the big 2026. Full-fledged story inbound!

If you've played the demo already but missed the feedback link, you can reach it here.

Hello! I have updated the demo based on constructive feedback from players. Thank you thus far to those who have played the demo and gave me your thoughts :)

Updates include:

✧ Much faster type-text speed (nearly double!) so you no longer have to nap between passages

✧ The 'next' icon now appears a second into a new passage, so you can skip dialogue if you've read all of it before (or you're just impatient).

✧ Additionally, the 'next' icon has been changed from '>' to 'O' so it is easier to press on a touch screen or click on with your cursor.

✧ More conditions have been added to the Vessel and Player naming boxes to avoid awkward errors

Please note these updates do NOT reflect final polishing. This is just so the demo is easier to play, and I can focus on polishing the actual game.

Are you prepared to Reach beyond the spirals of the black mirror?

. . .

EXCELLENT.

TRULY EXCELLENT.

Are you prepared to Reach beyond the spirals of the black mirror?

. . .

EXCELLENT.

TRULY EXCELLENT.