RUSH is a good puzzle game that never gets too frustrating, and if you do feel a bit frustrated there's a simple hint system that either tells you if your signs are placed the wrong place or tells you where to place signs. However, the game is missing a cute creature like Toki Tori.
The 21 achievements were easily done, but I still had fun doing them. I should have added to the review that the frame rate tends to drop when you start the boxes in the larger levels. This, however, isn't that important since you aren't actively doing anything while this happens. You should still note that some of the loop achievements can be a bit buggy if the game lags.