Now the kittens are working in gemstone mines. Every time a mine cart unloads at the end of the railway track, they go down the stairs to collect the gems.
Each level has a grid of squares with colored gems occupying some of the squares. The objective is to connect gem mines of the same color by drawing 'gunpowder trail' between them such that when it explodes, the entire grid is occupied by railway tracks. However, railway tracks may not intersect. Difficulty is primarily determined by the size of the grid, ranging from 4x4 to 7x7 squares.
(=^･ω･^=)