Reactoonz by Play'n GO is a grid slot released in October 2017 with a 7x7 layout and a science-fiction theme. The game uses cluster pays rather than paylines: a win is made by forming a group of five or more matching alien symbols on the grid.
During play, flux capacitor symbols act as wilds, helping build winning clusters. When a symbol is part of a win, it is removed and replaced from above, which can create multiple wins in one round. Larger alien symbols can increase a prize when they join a winning cluster.
The bonus-style feature centres on Gargantoon, which charges through winning clusters and then lands on the grid to trigger chain reactions that can create extra wins. A demo version is available to play for free, making it suitable for practice before playing for real money.