There's several differences in the way the game engines work but the advantage Bruce Lee has is that the scatter symbols are copied across to the different machines rather than you needing a single scatter on all four machines to trigger the bonus round. Better still if you manage to get three scatters on all four machines on a single spin you get a 12x multiplier to go along with your bonus round as well.
The three sets of reels on the right hand side of the screen, if you watch them very closely it appears like its just one set of reels moving through the various windows much like on one of WMS "Colossal Reels" games. This is important because it means you can only get a stack of wilds on all three sets of reels if you happened to get them on the initial spin of the larger reels, which really sucks. When you have two scatters on the left hand reel set then the right hand machines all spin in super slow motion and stop seperately but I'm sure they still work this way in the background.
Add to this the games horrible paytable (WMS seem to be even worse than NetEnt for this!) and I'd say your only chance at a big win from this game would be the 12x free spins round. WMS have another Bruce Lee game, the exact title escapes me right now but I definitely much preferred it to this one and I'd recommend seeking that one out instead of wasting your money on this.