Bejeweled Blitz rules

I haven't quite worked out the logic behind Bejeweled Blitz. The instructions are close to useless. If you get 4 in a row you get a power gem. If you get 5 in a row you get a hyper cube. OK. Got that. So now what?

Here's a few "rules" that I have found from my brief exposure to this game (at least I think they are rules, it all goes by so fast I could be mistaken!!)

If you destroy the power gem in a row of 3 or more then you get a small explosion and (presumably) more points.

It took me ages to work out what a hyper cube does. If you swap it with an adjacent gem, then all gems of that type are destroyed with lightening-like flashes, and you get points for each one destroyed.

You can also get a multiplier which, when destroyed as part of a group of 3 or more, will multiply all subsequent points by that amount (2X, 3X etc). It can also be activated by being near a power gem when it is destroyed.

If you drag the hyper cube to a gem of the same type as a multiplier, then you activate the multiplier. But don't make your hyper cube part of a row of 3 or more because if you do, you just seem to lose it as though it was a normal gem. Bummer.

The piece that seems to be pure luck is whether or not a multiplier appears at all. I cannot work out what makes the multipliers (2X, 3X etc) appear, it seems totally random. Mine always seem to appear right at the end of the 1 minute when its too late to do anything with it. There is no way you can get much more than 20K points without using multipliers.

The only other thing I know is, if you go fast you get extra speed points. Big Whoop.

This is the most frustrating, but also addictive game I have played in a long while. Oh well, back for another 1 minute frenzied attempt at 100K...