The tracker follow your mouse pointer, press to shoot. You need to get the cubes. If your ammo reaches 0 you can't shoot. Press R to get 30 ammo slowly. The cubes come at 7 seconds. Do not use R if your ammo is 30, it will just waste your ability. The mode is the type of aim you have, you'll start as regular.
What modes do. ( all other modes are regular but take up 2 ammo and have an ability) Regular is a normal shooter. Hybrid has a ability which spawns small 3 lava spinners. They move side to side and when cubes touch they vanish. They disappear after 20 seconds and puts the cooldown on 20 seconds.