Odyssey to the moon

There is an alien invasion and the government wants to put a shield around the earth, but the heroes forget the activation codes of the shield and thats when you appear. Your mission is to reach the moon and activate the shield, but ... There are aliens waiting for you. Will you be the hero of this story? ITS YOU, YOUR ROCKET AND YOUR GUN, good luck. So this is bullet hell (?) I guess idk about game genres ... Note 1: if the game is in Spanish and you dont speak Spanish, let me know Note 2: my english is bad Note 3: This is my first "formal" game :D