BreakthroughBreakthrough followed Martin Medema's explosive elimination game Explocus. The 'explosion' mechanism had been published in Games & Puzzles, in a game appropriately called 'explosion', and he beat me in turning it into something better than that.
The concept of 'exploding' forwards suggested a race game so I went to work and eventually a 9x5 board with two 'walls' that had to be scaled emerged. It's an unusual game for me, but it turned out nicely. Men move diagonally, single or in pairs. Squares 'explode' their content orthogonally sideways and forwards. Proceeding from the 'far wall' is only possible by means of an explosion, which will shoot one man forwards. The object is to reach the opponent's back rank.