From the steam page
Hidden areas to unlock Simple strategy
★B5 Hidden areas
1.After going through B4 and getting the 'Power Shot' ability, go back to B5 and go to the right to see a glass that can be destroyed with 'Power Shot'.
2.Enter the room behind the glass and destroy the three drones in the room to open the locked door.
3.Enter the room behind the door and you can interact with another door in the room to access the hidden B5 area.
✦4.B5 Boss must use Power Shot to attack the purple glass to deal damage to the boss.✦
★B4 Hidden areas
1.After getting the 'Double Jump' ability in B3, go back to B4 and go left at the beginning to the room with many orange crates.
2.Use the two jumps to jump over to the ventilation panel in the upper left corner. After destroying the panel, continue to the left to reach the hidden area of B4.
★B3 Hidden areas
1.After acquiring the Air Dash ability in B2, return to B3 and go to the incubator at the top left of the level.
2.Make a double jump + air dash to the left to reach the spot with the glass.
3.After shattering the glass with a Power Shot, enter the room with the door, which you can interact with to enter the hidden area of B3.
★B2 Hidden areas
1.After passing through B1 and gaining the ability to 'wall jump', go back to B2 and leave the chainsaw area to find a platform above you.
2.You can use wall jump + double jump to reach the platform above.
3.Alternatively, you can first jump to the higher red falling platform and then make a two-step jump + airborne dash to reach it.
4.Next to this platform is a cracked wall, use the power shot to break it and enter.
5.Use the wall jump to get to the upper left vent, break the vent panel and go further left to interact with the vent without the fan blades to get to the hidden area B2.
★B1 Hidden areas
1.When you reach the platform with the red iron, you will find a hole above it.
2.Double jump up and follow the path to find the scientist and the switch to turn off the current trap.
★Open B6 Hidden area
1.Clear the hidden area of B5~B2, the button to B6 will appear on the switch screen in the lift room. The button to B6 will appear on the control panel in the lift.