Complex sentence: To make the game more interesting, Cook added the gumball bombs and tweaked the mechanism that caught them--he first tried a player-controlled claw, then an item that traversed the pipes before finally deciding on crosshairs for the player to fire.
Split into simpler sentences: To make the game more interesting, Cook added the gumball bombs and tweaked the mechanism that caught them. He iterated through prototypes including a player-controlled claw and an item that traversed the pipes before finally deciding on crosshairs for the player to fire.