~Arrow keys to move the base (red colour) ~Click to move the target (blue colour) ~Space to shoot -方向键来移动红色方块· -点击来移动蓝色方块 -空格键射击 ~Angle and Gravity is adjustable ~Angle will be 45° if not adjust -可以调角度和地心引力 -不调角度则会是45°
Formula from wikipedia 公式在维基百科 https://en.wikipedia.org/wiki/Projectile_motion But looks like not accurate 看似不太准确，看看就好
