After a year of work there is now a major update to the game. Most of the game has been updated or improved in some way, mainly involving new or better assets, animation, audio and level structure. Some areas are new, most have been re-arranged to make things clearer or more fun.
The code was updated to use Unreal Engine 5 (previously it was 4). The main features we gain from this are Nanite, Lumen, and virtual textures. Lumen gives us dynamic lighting everywhere instead of baked static lights but means the minimum requirements in order to run the game have gone up. On my machine with an NVIDIA RTX 3050 with epic settings it takes around 10ms for each frame. With baked lighting on Unreal Engine 4 the cost was under 1ms.
Nanite and virtual textures don't appear to have any great cost and improve streaming level load time greatly. They also appear to lower the peak GPU RAM.