Ra is, of course, a fantastic board game and the app captures its essence well --- but it goes further to add so much visual traffic that the game actually makes me nauseous. The "shifting sands" graphic that underlays the game board simulates the sensation of carsickness and is extremely distracting.
Moreover, the unnecessary "sand swirl" that takes up the whole screen when a Ra tile is drawn might be passable if it didnt happen as often. It would be much preferable if, for example, the tile merely lit up or shook with a strong sound cue. As it is, theres a churning, distracting background and a constant in-your-face interruption that really come between the player and the game.
Flop House Cat about Reiner Knizia's Ra, v1.4