|Total Coins||Coins from Enemies|
Despite Wet-Dry World being split into two areas, if you get all of the coins in the first area, then you will get the 100 coins star. None of the coins are really difficult to get, so this could potentially be one of the easier 100 coin stars in the game, simply from the fact there’s a lot of coins. It is pretty much the best option to start the coin collecting when the water is at its lowest level, so jumping in the painting as low as possible is what you want to do. Since there are no fundamental changes to the landscape of the level between stars, it doesn’t matter which one you pick when doing this.
With all of that out of the way, start your coin-collecting by defeating the Skeeter near you at the very beginning for three coins (3). Nearby the large/tall wooden platform, there are some breakable blocks along the wall, so punch all four to get another twelve coins (15). Head all the way to the end of the ground level and break open the yellow box that was the second secret for [Secrets in the Shallows & Sky] for ten coins (25). Hop up to the first tier of the main structure of the first area, where you can find another Skeeter for three coins (28). There is also the Blue Coin Block here, which spawns six easy-to-collect Blue Coins (58).
That wraps up the ground level stuff here, so head to the platforms with the Amp circling it to hit that Crystal Tap and raise the water. With this, you can jump on the wooden platform near where you started, which has a yellow box on it that contains three coins (61). Hit the purple switch on the same platform and get on the next platform with a Crystal Tap, touching it after collecting the five coins there (66). The higher water level allows you to get to the third tier of the main portion, where you can collect eight coins around the raised platform with the Amp (74). Jump on that raised platform and hit the box to get another ten coins (84).
In the far back, there is a bigger block you can push, which allows you to reach the yellow block there for another three coins (87). Get to the top of the cage next to hit the block there for another ten coins (97). Long Jump to the upper section of the main portion of the first area, right by the slope with the Crystal Tap, where five coins will be sitting there (102). For the final bit here, you will want to take out the Chuckya enemy, who drops five more coins (107).
That’s all you have to do to get the 100-coin star, but if you want a little more, then get the water level to the highest point via the Crystal Tap, then use the cannon/tunnel to travel to the downtown area. There are two Skeeters here, for another six coins (113), as well as eight coins sitting around the small statue in the square (121). You will also have the eight Red Coins and two of the buildings have five coins each on them (147). The final coins are found at the top of the second area, which is accessible via a pole on top the building housing the Red Coin star.