As you may already know the game is pretty simple and you can complete it quite fast. But if you somehow still have trouble completing it, so much trouble that you actually decided to check out the guide section for solutions and eventually arriving here, on my guide (it's not like they're many of them), then here's my advice.

All you can do to easily complete it, is to stay in the middle of road, avoid borders and try to shoot mostly in the middle of the horde, of course you'll have to shoot on your sides from time to time but make it pretty quick and then return the fire to the middle of the horde or otherwise it will overwhelm you, that's all the advice I can give, you'll probably get through the game like butter.

There is no step two, just enjoy the game and try getting as big a highscore as you can. Thank you for reading my guide.