Here is the full list of all 18 Harpoon Shooter! Nozomi achievements.
Watched through the end roll
Acquired 5 weapons
Cleared 3 times (all difficulty levels)
Cleared 10 times (all difficulty levels)
Cleared 30 times (all difficulty levels)
Defeated 1000 enemies
Defeated 5000 enemies
Defeated 20000 enemies
Collected 500 balls
Collected 2000 balls
Collected 5000 balls
Discovered 5 Secrets
Discovered 12 Secrets
Discovered all Secrets
Received a smile 10 times
Received a smile 50 times
Received a smile 100 times
Cleared the Easy mode without getting any sweets (Arcade Mode)