There should be a 100%-200% base key bonus on Comet Chase.
Reason being: If you use some items in this mission (which can be vital to get out of situations where the comets forms a “U shape of death” around your spacecraft - you’d either use your Lives or other items to get out of that one)
Played a Comet Chase recently. When I calculated my keys used for that, I lost 5 keys.
The bad part is, The items I used were on Shady Dealer sales, so the price got reduced by 45%, that’s why I only lost 5 keys. I would’ve lost 44 keys if I used Galactic Store counterparts of those items.
The comets tend to form an “U shape of death”, which can’t really be predicted since you’re basically seeing that U from the top down, and no one can suspect the 2 random pieces of comets to be the start of that death sentence (it’s random, how can you tell). You’d lose at least 4 keys per level, while doing an easy-mid mission per level only gives you 2.
(Yes, this was an easy-mid mission, only about 50% difficulty)