There's actually more interaction than you might think, though it's not necessarily well explained on screen. For example, the more eggs you destroy (via pop bumper hits), the more valuable the egg-related modes are (Derelict Ship and Queen's Nest). The value of Ambush Multiball is increased by the number of Lifecycles you've completed before starting Ambush. The value of Sentry Guns Multiball is increased by the number of weapons you've collected before starting SG. The value of each movie's mini-wiz is based on how you did in that movie's modes. I think there are a few other relationship links like that scattered around.
Many of the modes also have hidden niceties (and/or penalties!). For example, Find Jonesy scoring is based on how many shots it takes you to find the cat... the fewer the better. Or during APC mode, besides the lit shots, completing the APC drop targets spots the current shot and also increases the value of shots for the remainder of the mode. And the Recharge target is always helpful during modes and multiballs.
And there are miscellaneous fun tidbits, like the 5,000,000 "Super Skill Bonus" for making 3 distinct skill shots in a game.
We tried to design the game to have enough depth to be interesting, without needing an encyclopedia.
Quoted from RussG:How many modes and video clips for those modes you think there are in total?
There are 10 primary modes (2 of which are mini-wizard semi-multiballs) and 5 other multiball modes including the final wizard mode, All Out War. I no longer have access to the raw assets, so don't quote me, but my memory is that there is +/- 25 minutes of video content, across several hundred clips.