Planet Smashers is a vertically scrolling shooter similar to Xevious. Power ups can be captured by destroying cargo ships. Power ups include improved weapons, shield restoration, and cloaking ability. Cargo ships also drop warp capsules that the player needs to collect in order to proceed to the level boss.
The game has a unique feature called Earth Shield, which decreases every time an enemy ship passes by without being hit. If the shield is destroyed, it's game over.
Gameplay involves navigating through levels while avoiding enemy ships and capturing power ups to aid in progress.