Alien Swam Beyond Insane. Introduces the increased difficulty. The mod allows the customization of AI directed spawns (wanderers only for now) via a config file. This makes it possible to change the amount as well as the type of aliens spawned.
Stats:
http://naru.mooo.com/bi-stats/
Download:
bin https://docs.google.com/file/d/0B7pI083Z9asoUnFvSkJBNWNhdE0/edit
src https://docs.google.com/file/d/0B7pI083Z9asoWXFQUVBzb3NQMUU/edit
cfg https://docs.google.com/file/d/0B7pI083Z9asoLXFSaHlScnkydDA/edit