For the online game, only grab the blue batteries as they have a cumulative effect on your score--the first battery is worth 50, next 70, then 100, and the more you grab, the more they're worth. If you accidently grab a battery of another color the next blue battery goes back down to 50.
For the in-park game, you can't hold down the trigger on the DL version. You have to keep squeezing it. Each different shaped target is worth a different amount of points. The circles are worth 100, squares are 1,000, diamonds are 5,000, and triangles are 10,000. If the neon light around it is lit up they are worth the next higher point value, with the triangles being worth 50,000 (there are a couple of hidden 50,000 point targets on the ride). My highest score w/o stopping is over 500,000, though my average right now would be in the 300,000s. I mostly shoot at triangles and diamonds, trying to hit them multiple times. I only hit circles to activate other targets because some targets pop up after hitting them.