IGN has posted a interview with Ghost Squad creative producer, Yosuke Okunari.
“There are more than 20 types of weapons with different powers and performances. The player’s level is increased according to the experience value obtained by playing the game again and again. When your level is increased, more routes will be added within the same mission, but you can also obtain weapons as another benefit of increasing the level.“Yosuke Okunari
The full interview can be found here.