Here is the full list of all 13 Captain Frogger achievements.
Defeated the frog for the first time
Killed 100 frogs
Killed 1000 frogs
Killed 10000 frogs
Killed 50000 frogs
Get SSS rating
Get SS rating
Get S rating
Beaten for the first time
Beaten 100 times
Beaten 10000 times
Beaten 50000 times
Beaten 1000 times