You play as the agent Hans Kloss himself, who has to infiltrate a Nazi base in order to recover plans of the V1 rocket. On your way, you're menaced by insta-killing machine guns activated by tripwires (they can be switched off, but only for a limited time), and tracked mines which randomly drive onto the screen and deplete your health and drink meters. Oh, did we mention you need to eat and drink frequently or else you die?
Gameplay-wise, the game is a classic example a genre known in Poland as labiryntówka ("maze game") or komnatówka ("chamber game"): a Platform Game where half of the challenge comes from navigating the mazelike Flip-Screen Scrolling game world, and figuring out the exact right route to take without getting stuck.
The game features the following tropes:
- Game Over: "Gra skończona KLOSS!" ("Game over KLOSS!")
- Gotta Catch 'Em All: The game has you collect pieces of the plans.
- Interchangeable Antimatter Keys: There are lots of keys around, but they're one-use, so opening the wrong door will get you stuck in an unwinnable situation.
- Nintendo Hard: Trying to navigate the levels and manage keys is difficult enough, and the platforming challenges can be really tricky.
- Protagonist Title
- Trial-and-Error Gameplay: You will keep dying or getting stuck a lot until you manage to map out the entire game and figure out the right route. Once you know where to go, the entire game can be completed in 20 minutes.
- Unwinnable by Design: Plenty of opportunities to end up like this.
- Vomit Indiscretion Shot: Eating food when you're over 60% full will cause Kloss to vomit, and won't refill his belly.
- Wizard Needs Food Badly: Kloss may be the only secret agent who is in danger of dying if he doesn't eat and drink every 160 seconds. Thankfully, there happen to be mutton legs and coffee cups scattered around the base. The hunger and thirst counters also double as health meters, as they are depleted if Kloss comes in contact with the tracked mines driving around.