My 4 year old daughter really took to this game and had no idea she was learning to spell I'm sure.
The full alphabet is divided into groups of coloured tiles. The words are similarly colour coded so that a child shouldn't be put off finding a letter in a particular word if you show them that they just need to look at the colour of the letter first. Then they only have to search for the correct letter out of a small group of letters all the same colour instead of the whole alphabet. My daughter soon was keen to show she could do it by just finding the letter rather than the colour. Level 1 just starts spelling words like 'cat' whilst higher levels move onto 'pear' and bean' showing different sounds made by 'ea'.
A great precursor to junior scrabble.