Hudson's Adventure Island II/Game Mechanics hai2
From SDA Knowledge Base
General game description
You control Master Higgins on an island hopping adventure to save his lovely girlfriend Tina (or maybe he has a new chick in this game?). Each island consists of several levels. At the end of each level, there is a bonus game, where you get to pick one of eight circling eggs before moving on to the next level. The level Master Higgins is sent to depends on which egg is picked. That means there are several different paths through the game. There is also three warp possibilities in the game (on island 1, 3 and 5). Using a warp will send Master Higgins to the next island.
Version differences
The difference between pal and ntsc has not been reviewed in detail. However, they seem to be very similar except for the frame rate. There is at least one enemy in the ntsc-version that is not present in pal though.
Life meter
You start each level with 11 bars on the life meter. A bar disappears from the meter every 180 frames. Picking up a fruit (no matter which type) adds two bars and resets the timer. This means a fruit can prolonge Higgins' life meter from 360 to 539 frames, depending on when the fruit is picked up. Each bar adds 7 frames of countdown at the end of the level.
Movement speed
The character speed is shown in RAM-address 1DD0. The speed increases/decreases in chunks of 4, giving 0, 4, 8, 12, 16, 20 and 24 as valid speeds. When Higgins is on foot, his fastest speed is 16. On skateboard or with the blue or red dinosaurs, the max speed is 24. The flying dinosaur has a max speed of 20. The speed doesn't change every frame. The number of frames before the speed changes depends on several things. To keep things simple here, it will only be said that you have 4 frames of inertia when moving at 24 speed with the blue or red dinosaur. That means it's easy to dispatch of enemies by firing off shots without losing speed (as opposed to for example the first Adventure Island game for the nes, where shooting always means losing speed).