Forget about the graphic, this game have nice mechanics. There's no tutorial like click this and there, but the player learn something new with progressing through the game.
Some tips after reading some comment, credits to original poster:
1. Press space to see pointer to help find guffin (for progressing the game and can fully recover health and oxygen)
2. To kill fish efficiently, cut the jaw, it's the red box (you can see it from the breathing bubble too), and be careful the fish can attack you
3. The long white line is the fish spine, attack multiple times to make the fish bleed and died, so so the body keep in intact, means higher money
4. The grey and green orb that sometimes appear on some fish give high multiplier
5. Press 3 in the free play to experience godlike bending reality weapon XD
6. Enjoy the game ^^
Finished 3 hearts medal with cheats on last row levels, still feel proud of myself XD
I wonder if I can put this on my cv, for example to pay attention to small details =P
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