I can find something good in every game, so I have none that I hate... It's easier to answer what are overrated, but we have other threads for such.

If you purposefully put the ball on the lower playfield before opening the gate to avoid the outlane, and then bitch about draining it when it comes up, that's not an issue with the rules.

Hard games are the ones that keep me coming back, but there is a point where I feel like I'm just knocking my head against the wall. BH is tough. IM is right there too, and frustrates me far more. Being a masochist I own both.

I agree on the rules, the game should do a better job letting you know what to do. I was playing it last night, and all I wanted to do was to combo the ramps a few times, but every single ramp shot went into the freaking cannon. I nearly walked away from the game.

On BH, on the upper playfield if you you hit all 4 standups on the right and then get it in the right inlane you open the return gate and are thus clear for a risk free trip to the lower playfield. If you get it down there before opening the gate, you have still have the ability to open the gate by hitting all drop targets on either bank. The bottom playfield is used for multipliers, ball locks, and special. All together the use and rules of the lower playfield are fairly brilliant, IMO.