"Bonus"

[slysy]

Anyone know what this means? When you select a level, it says bonus in the bottom right and it looks like there are two slots for it...

[justindcovey]

There are actually three slots. It lists the bonuses you have gained beating those stages (no miss, 100% damage, and no bomb.) completing any two of these will unlock the harder b, c, d, & e stages.