Entropy Turtle: Is an Owl's eye with lower ability cost that you can play extra copies of without needing a 2 card combo. Broken. Also pande is community slang, not a game term and imunity to it seems odd.
Green Turtle: While not strictly better than Forest Spirit, this card is really pushing the power level to 11. Plus, its upped version means that there are now 2 different effects with the same name in the upped meta. Perhaps don't call it growth?
Red Turtle: Strictly better than Red Nymph in cost, ability cost and base attack, strange that the effect doesn't up though.
Water Turtle: Seems perfectly fine apart from the imunity. If Physallia has none, why should a turtle?
White Turtle: Looks to be an increadibly powerful repeatable buffer, not sure how balanced.
Yellow Turtle: No reason for it to interact with Shockwave, make it delay instead.
Black Turtle: An efficient body AND darkness' bolt on a stick. OP!
Turquoise Turtle: Please explain how the ability works from a thematic standpoint because I'm lost.