[QUOTE=a]When do you need to press an additional button?[/QUOTE]The L and R buttons were used to help you make sharper turns in Blue Storm, although the N64 game had that function, too. However, in Blue Storm, unlike Wave Race 64, steering was noticably harder when using the analog stick alone, so using the triggers to turn in the GC game was a necessity.
Blue Storm was harder to steer, but only because the wave physics were incredible. The only reason it's more difficult than the 64 game is because the technology allowed it to be more realistic. It is harder and has a less arcade-racer-like feel to it, but it is a great game if you give it a little time.