Lock A Luck, a traditional retro slot game for the purists out there.
In this game: when 5 adjacent reels roll up you activate the locked reels where identical symbols could appear. Plus the expanding adjacent reels increase to reward bigger wins.
Game details: take a step back to the beginning of slot machines with the Lock A Luck casino slot. Created by Microgaming, there's 5 reels with 243-ways-to-win.