No matter how old you are, you'll probably remember seeing Optimus Prime and Megatron duking it out in one form or another – as a cartoon, a film, or in video games. Now software provider IGT has brought the battle to the reels in this online slot. Hopefully you can transform these hulking alien robots into some cash. Whether you prefer the Decepticons or the Autobots, this Transformers: Battle of Cybertron slot has enough characters from both sides to satisfy, and a whole host of bonus features too. There's a good return-to-player percentage, although it can be variable. Read on and get ready to roll out.

From the 1980s animation and action figure incarnation to the more recent movie universe, Transformers are never far from our screens. This IGT game seems to be based more on the original series than the movies, given the look of the characters. Cybertron, as any fan will know, is the home planet of all transformer kinds, and it also forms the very detailed backdrop for this game. Graphically, it's been very well done. You'll recognize characters like Bumblebee, Megatron, Optimus Prime, and Soundwave, and all the important information is presented clearly at the bottom of the screen. The invisible reels are a nice touch as well and give the whole game a more futuristic feel.

There are five reels with 40 paylines on offer, and a host of bonus features too, which we'll look at in a moment. The characters themselves aren't worth the most as far as standard symbols go, however – for the biggest standard game payout you'll need the Transformers symbol. There's a variable 92-96% return-to-player on this slot, and you can bet anything from 0.06 coins to a titanic 600 coins per spin. That makes it good for serious games or a few casual spins, although there's a lot of focus on the bonus modes for payouts, so you'll need to get these active to really win big.

If you can get three of the planet Cybertron symbols, you'll enter the free spins mode. Here you can choose which robot you prefer to get varying multipliers and free spins. Statistically, they're not too different ultimately – it depends on how lucky you feel, and whether you want to balance increased chances with low multipliers or vice versa.

The free-fall feature is pretty standard, but it’s a good one. It means that all symbols on a winning payline vanish before being replaced with more symbols, so you might get a few more combos in to boost your win. The mystery feature can happen at random. An Autobot or Decepticon will appear and either help or hinder your game. Actions can range from Optimus Prime destroying all the Decepticon symbols on the reels to Ratchet giving you a final bonus symbol for a free spin. While you can win some big payouts, the random nature of the mystery feature might not be for everyone. Either way though, it's a well-made, enjoyable slot.