I propose that we add systems of procedurally generated underground caverns, as well as new machinery and new enemies that are better suited to them.
Machinery:
- Seismic Surveyor
Used to find where caves are by pounding the ground. Similar to Radar. - Shaft Boring Machine
Used to first give access to tunnels. - Ramp
Used to allow transport belts, rails, and players easy access to tunnel system. - Tunnel Boring Machine
Used to create new tunnels in a straight line. Can also maybe place transport belts behind to handle byproducts. - Minecarts
Smaller, more maneuverable versions of trains better suited to narrow tunnels.
[TBA]
Notes:
- Tunnel walls can be mined slowly by hand. Resources are found in the walls, and also on the ground underneath them once mined.
- Resources are much richer underground, to encourage players to explore and make use of tunnels.
- Certain caves are actually alien burrows, with rooms and spawners.