It looks like Valve isn't hurrying to make a new Portal game, but an upcoming unofficial Portal 2 mod may be the next best thing.

The mod's filesize is too large for Steam Workshop - hence its individual release.

Portal Stories: Mel is a free, story-based add-on featuring more than 20 new maps and a fresh narrative. All you need to play it is a copy of Portal 2.

The mod has taken eight talented Portal fans more than three years of tireless development to complete.

It's currently due for Steam release on 31st March after earning approval via Greenlight.

Mel stars a new protagonist (yes, that would be Mel) and a new personality core in a story that explores the early years of Aperture Science.

Players will wake up years later after a short-term sleep experiment goes awry. You'll have to work out what went wrong while attempting to escape.

The blonde-haired Mel was originally designed to be the main protagonist of Portal 2 before being cut in favour of a return for Portal 1's Chell.

The character was then considered for inclusion as your co-op buddy in Portal 2's two-player campaign - before being cut for a second time in favour of android test subjects Atlas and P-Body.

Watch a new trailer for the mod below: