I was afraid I had to type lots of critic about the perspective here, but since this is basically a scanfix, that isn't an issue since it's part of the original artist's view (which you always need to respect).
So what's left for me to say is that I like the scene, but there are still a few points worth improving. One is the outlines on the characters. Especially on the green-ish shirt, the grey outlines are downright ugly. Match outline colors with the colors they eh.. outline. Or go for black (although I hate that too).
Furthermore, see if you can slam a sort of concrete texture on the pool floor and sides. Especially because they have 'cheap looking' colors, you need a bit of detail and depth, otherwise they're just big junks of plain color, which feels unnatural and thus unpleasant. You might also want to try out some gradients or dodge/burning some areas to make it more lively.
Thirdly, downsize the contrast between the tiles and the space between the tiles. Remove the bevel effect there, because it doesn't match the vectorized look of the rest of the background.
And finally, fix the perspective on the bottom right corner.