1) INTRUSIVE ADS - GAME RESETSThis map puzzle puts a banner ad at the bottom edge of the game, right where a child's hand may rest while she is solving the puzzle. My daughter was solving the puzzle, and accidentally touched the banner ad. It ripped her out of the game, popped open Safari, and then popped open the App Store. It was a whirlwind of B.S. trying to shut the intrusions off and get back to the puzzle game... Then it got WORSE! When she finally got back to the game, it had reset. It didn't save her progress, so she had to start the puzzle all over again.So basically the bottom edge of the screen is an ad that will tear you out of the game, then erase your progress.2) PUZZLE PIECES DISAPPEAR OFF OF SCREENAs with their Japanese puzzle map, this app has problems with pieces going missing. You can accidentally drop a puzzle piece off the edge of the screen, and then you'll never get it back unless you restart the whole game. Furthermore, you can drop a piece behind the scoreboard (but it can be retrieved by stroking a finger over teh scoreboard *IF* you know you dropped it there.), and you can drop a game piece behind the super-intrusive banner ad (and that piece can not be retrieved without restarting the game). This is a problem in their U.S. map and their Japan map app, too.Note to developers: Please fix this in your Japan map app, too. The missing pieces problem is very frustrating, because you often can't tell you lost a piece until you've almost solved the puzzle. Has anyone ever bought a puzzle at the store and discovered a piece is missing? You only find out when you've already done almost all the work. It gives a feeling of deep disappointment right when you should be feeling great accomplishment.3) STATE NAMES HIDE THE SHAPES OF SMALLER PIECESSmaller states like Massachusettes are covered up by their names. This makes it extremely hard for beginners to see the shapes and recognize their correct placement on screen.4) ACCENTED PRONUNCIATION (a mild problem)Some of the state names are pronounced with a Japanese accent. It isn't a terrible accent (the speaker is very good with English,) but a game developer should know better than to use a non-native speaker. The pronunciations are clear, but quirky: "Ver-gee-nee-ya" instead of the correct way ("Ver-gin-ya") for Virginia, etc. Again, not awful, but a little "off." Developer needs to sit down for a couple of hours, and pay a native speaker to say the states into a microphone.I'm tring to help the developer here by revealing the problems in this (and the Japanese puzzle, too) app. One more thing: At the top of the screen it should read "USA Puzzle Challenge" not "Challenge USA Puzzle".