About S. Bonuses[]
S. Bonuses are special/secret actions you can complete which will give you extra points. They sometimes offer access to additional weapons or areas, or have other helpful effects. There are 21 S. Bonuses in the game: 3 in each of 7 stages. The game internally keeps track of each S. Bonus you have found, both for your current playthrough ranking, and overall for your pilot.
When completing an S.Bonus, an icon will appear in the bottom-center of the screen, illuminating up to 3 angled slots. The illuminated slots show you which S. Bonuses you've achieved in that stage. Once this icon appears, you have credit for completing the S. Bonus - if you die and return to a position before the Bonus, you do not need to complete it again to count towards your total. However, completing it again will award you the appropriate point bonus again, along with any other affects.
In the Japanese version of the game, achieving all 3 S. Bonuses within a stage (cumulative across all playthroughs as the current pilot) will unlock that stage in the Free difficulty's Stage Select mode.
Obtaining any 15 S. Bonuses in a single play will unlock Unknown Fighter I after reaching a Game Over, whether that's from dying or beating the game.
Each S. Bonus is detailed below.
Stage 1[]
#1: Destroy all of the neon signs.
#2: Destroy at least 50 ships before the gasmask sign, then destroy the rocket-booster Uhus that will appear. The 2nd one is the Bonus.
#3: Destroy the bottom part of the midboss. This directs you to the "undercity" section, and an alternate version of the stage 1 boss. This version of the boss can deploy a Juno.
Stage 2[]
#4: Quickly destroy the hovertanks near the beginning. The red one is a Bonus.
#5: Destroy 10 units mounted on the first turret-loaded train car.
#6: Destroy 10 units mounted on the second turret-loaded train car.
Stage 3[]
#7: Quickly destroy the disc-backed enemies before the midboss. Red is Bonus.
#8: Destroy 8 rail-mounted enemies during the midboss fight.
#9: Destroy all of the falling enemies after destroying the elevator. If successful, a Flash will appear.
Stage 4[]
#10: Destroy the submarine hull, then the core after it detaches. If successful, it will drop a Juno.
#11: Take the lowest route after the midboss. Destroy the red sliding mech.
#12: Destroy the reactor floor, just before the boss. This will damage the boss before you fight him.
Stage 5[]
#13: Destroy all 6 crane arms on the wall.
#14: Knock down the midboss four times. If successful, a red crate will appear containing a Flash.
#15: Destroy the red laser ship that flies in the foreground. It can be faced directly if you destroy all fighters in this section.
Stage 6[]
#16: Destroy 20 enemy fighters, and then the red ship that appears, before destroying the second booster.
#17: Destroy 3 launch tubes that appear from the rocket, after destroying the first booster.
#18: Destroy the tiny disc that emerges on top of the boss, then destroy the boss and the enemy that follows.
Stage 7[]
#19, #20, #21: Destroy each of 3 red ships before the boss. If the first two are successfully destroyed, the third one will be carrying a Juno.