Press the green flag and answer the question posed by the character. Then, press and hold space or the up key to jump. Avoid the rocks in the grasslands, the ice spikes in the mountains, the mini-volcanoes in the volcano level, and the fire in the sky. The other moving sprites (grass, rocks in the volcano and mountain biomes, cloud pieces, and clouds) are harmless. The question mark boxes are power-ups that give you extra amounts of life or higher jumps. They also speed up your game temporarily.
