brief overview:
NEO Basudusho features 6 to 8 different stages. All the stages are shown in topdown view with a tilted camera to get some orthogonal perspective (like in Neo Contra/Alien Syndrome and so on). --> Picture
The stages have different styles of course and range from modern tech, to rusty tech, alien style, caves, sand fields, uncommon alien architecture and other stuff. The locations can be outside, too. It's not necessary, that all locations are inside corridors. They also can have different height levels. But it has to be determined, how to avoid problems with ramps or uneven ground. There are some difficulties about what should happen, if the player walks up a slope and shoots. He'll either shot directly in the ground before him or the shots adjust to the underlying ground angle, which can cause other problems. So, on first glimpse, slopes should be avoided, but if the games misses them, it will make level design and the overall look quite boring.

stage ideas (in no particular order):

orbital research lab:
A formerly clean and bright research station orbiting over a foreign planet. But some things gone wrong. The player docks at the airlock to get some clues. Soon he finds out, that the station is under attack by some sort of aliens (sounds familiar, eh?). All security systems have gone wild. Mech stuff and security robots and soldiers are around everywhere attacking even the player. Lots of areas are shut by security. Need to find key cards, get security systems out of the way and stop the selfdestruction and so on. On the other hand there are the aliens, which are uncomfortable, too. Some areas have almost no light anymore and are dark and creepy. Maybe there are dead bodies everywhere.
Nice ways to use depth and parallaxing effects with walkways and the architecture of the space station. Think of huge hangars, deep tubes into the void and so on.

desert ruins:
A little bit like the desert levels of Metroid Prime. Ancient ruins and architecture, covered in sand and dust. A mix of outdoor desert stages and indoor sections. Enemies are sandworms and other organic creatures. This stage is a little bit more open, has some riddles to solve and new kinds of enemies... More to come.

bridge chase:
In this level the player mounts a hoverbike thing, chasing a huge train. The train is little bit like the huge spaceship in R-Type. The entire train is the enemy and boss of this level. In order to succeed the player needs to destroy all the guns and superstructure. He can move around and shoot like normal, but there's a scrolling background which leads over bridges, through canyons and over valleys and so on. Should be fast paced and action filled.... More to come.

abandonned city:
The player enters a mining village, which lies abandonned. It's like a city with broken and torn down houses. The way leads through tunnels and through houses to the main tower. This stage is more about clever fighting and finding a way. Some defense systems still work.... More to come.

mining system:
A dark and desolate mining system. Everything is rusty and small. Security systems work at some points. But there also some horrible creatures.... More to come.