Early programming has begun for SOUL NINE. I anticipate the final product will take a long time to develop, but I hope to have something playable out by the end of 2026.

I don't have too much to update about at the moment, since it's been a slow end-of-summer and start-of-autumn. However, I can begin explaining some early concepts for mechanics within the game.

Today's particular topic of discussion will be the time and weather, something I've done a lot of thinking about for certain regions of the Underground.

SOUL NINE will have a calendar system. At the moment, it is using the Gregorian calendar for the ease of writing, but this may change if it suits the game and story better to use a different calendar. Given that the Underground is contained within a mountain, any subterranean climate would be largely independent of the surface. However, large-scale temperature differences would still have an effect. During the winters, the temperature of the Underground will lower substantially, and during the summer, it will rise.

Artificial sunlight has been constructed for the purposes of agriculture and the maintenance of healthy sleep schedules throughout the Underground. These systems run on a 24-hour clock. While some areas of the Underground have their own natural light sources, with Hotland being the primary example of a naturally well-lit area seen in Undertale, the lighting in others would have to be manually created.

In SOUL NINE, the clock is sped up for gameplay purposes, though by how much I am still unsure. I have begun leaning toward 48-minute days, with each hour lasting two minutes. For a little under two-thirds of the day, the lighting will be on. As night falls, the bright lights are slowly switched off and replaced with dimmer ones, simulating moonlight. It's no sun and moon, but it does the trick.

Some regions of the Underground have obvious signs of hydrology. In some of Waterfall, it rains constantly. However, in others, the source of the water is less clear.

Snowdin Forest is covered in snow with no clear source. In SOUL NINE, this is used as the basis to establish a system of internal climate within the Underground. The cave is large enough to support its own weather systems (which is not entirely fantastical, as some real caves have weather systems of their own).

SOUL NINE aims to give the player a decent degree of control over your protagonist. You will be able to switch clothing items (with different clothing choices potentially displayed visually in the overworld). This does come with the complication that certain clothing will be unsuited to certain environments. You wouldn't wear a tank-top to a glacier and you wouldn't wear a fluffy coat to the magma chamber of a volcano. The details are fuzzy, but there will be systems in place to ensure you are dressed accordingly. There will be shops in different regions with the appropriate attire, and potentially items you can use to alter your tolerance of temperature. Perhaps you can wear a fluffy coat to the Chamber after all.

The following is a list of some of the regions of SOUL NINE's Underground, and the kind of weather to expect in them.

• Basalt Lake - Located north of the Royal Laboratory, the Basalt Lake is a massive lake of lava surrounded by cooler basalt flats. Due to its proximity to Waterfall and the cool air coming from both it and another region north of it, the air around the lava is remarkably temperate. This remains stable all year and so there isn't much variety in the weather experienced.

• Snowdin Forest - One of the closest regions to the flowerbed you fall on, Snowdin has a decent amount of temperature variation. During the summer, the snow doesn't quite melt, but new snow does not fall often at all. However, during the winter, blizzards will lower visibility and drop temperatures to a frigid level frequently.

• Arkadis - South of Snowdin, Arkadis is home to lush fields of subterranean grass which double as both scenery and food. The temperatures are more variable here than anywhere else in the Underground. The artificial sunlight glows blazingly hot during the summer months and during the winter, the cool air from Snowdin bleeds in and can cause it to occasionally freeze over. This serves to assist in crop rotation, as some plants in Arkadis only grow in the cooler months. The closer to Snowdin, the cooler it is, and the closer to the Underbarrier (more on that at a later date), the warmer. Rain is common in Arkadis and due to the formations at the ceiling of the caves, the winds can grow fierce. Certain minerals conduct electricity and cause tremendous bolts of lightning to discharge from stalactite to stalactite.

Most of the weather will be primarily visual, but sometimes can present a danger. As stated before, blizzards can lower temperatures to bleak levels. When this is combined with the already variable temperatures and night-time it can create inhospitable periods in an area north of Snowdin.

That will be all for now!