A Space Shooter for 2 Bucks! is a vertically-scrolling shooter set in space and with a humorous tone. The player controls the testosterone-pumped commander P. Jefferson, the space pilot of the USS Eradicator, who sets out to destroy X, the Supreme Alien God Emperor, and bring peace to the universe. Along the way he is accompanied by Edgar IV, the ship's British, sentient navigation system. The space ship can freely move around the screen while the background scenery scrolls vertically and many waves of enemies need to be defeated. There is a basic weapon with double cannons, different special weapons and an overdrive function. Between missions there are static cut-scenes showing the characters with voice-acting.

Instead of a linear path, the game offers a map with sixteen levels that are mostly available right away, divided over two zones. There is a recommended path as a difficulty level is shown for each stage, but it is also possible to play them in any order. Generally there are two types of missions: ten side missions to earn upgrades and experience, and six story missions that end in a boss battle with the ability to assimilate the boss weapon afterwards. The special weapon can then be selected for other missions and comes with a limited amount of energy. Missions can be replayed to earn additional cash and purchase new add-ons.

Support power-ups restore the ship's energy, energy of the selected weapon or shield power, slow down time, offer a bomb that explodes in multiple bullets, make the ship launch regular missiles or firework missiles for a while, temporarily upgrade the main cannon or make it shoot faster, or make the bullets stronger. By defeating enemies, an overdrive meter is filled and when it is full it can be activated to clear the entire screen. Small blue orbs called remnants are the main currency and these are left behind by almost all destroyed enemies. Between missions a shop run by Jenna Velasquez can be visited to purchase upgrades (for the ship as well as the special weapons) and Jefferson constantly hits on her. There are four difficulty levels for the game and a New Game+ after completing it to restart with the earned upgrades right away. There is an endless survival mode next to the main campaign mode.