Don't stop shooting
I know that in some games, gunshots can be fired automatically. But in NullStar, you do need to lift a finger to make your gun go pew. By holding the right side of the screen, you can blast away at your enemies. The tip for you here is to keep that finger or thumb pressed on that side of the screen.
Remember that this is an endless runner so you're constantly in motion. This means that enemies will seem like they're coming at you pretty quickly. The last thing you want to is get killed because you weren't trigger happy enough.
There is no reloading or cooldowns. Just keep firing away, just like at the arcade machines. Enemies aren't just running at you, they're also firing weapons. And sometimes, the best offense is your best defense, and that's the case here, so go wild with the guns, gunslinger.
Get comfortable with the jetpack
Instead of basic jumping, you have a jetpack that you can use to gain some height as you move. It's extremely smooth to use and is a lot of fun. It also can save your life when you're going through the waves of foes. This is because they will shoot you from different heights.
And you need to defeat a certain number of enemies to advance. So this means that you'll need to practice with your special leaping ability and hit them right where it hurts while you're in flight. This may require some dodging too.
But remember what we talked about earlier; keep holding the shoot button, but just do so while you're also taking flight so you're guaranteed to kill the airborne enemies. But you do need to get comfortable with using the jetpack and making sure you don't go too high or remain too low. Steady tapping will help to keep you floating when you have more than one foe in the air to deal with.
Don't be afraid to dodge
The number of enemies you need to take out will grow as you progress through NullStar so it's easy to think you need to kill every single one that you see. This is not the case. Just take your time and play your game. If you need to dodge, then do it.
It's highly critical that you avoid getting hit at all costs. One-shot and you're dead. You are given a few credits where you can respawn, but still, it's wise not to be careless. Try not to worry if you miss a couple of the monsters. As long as you kill as many as you can, that's all that matters.
It's a bit of a balancing act, and I know that you want to beat the level and advance to the next. But dodging when you need to is never a bad thing. And when you have a great jetpack feature, juking your opponents can be smooth sailing.