Karamalz is a brand of Malzbier, so what we have here is a promotional game. Promotional games are mostly simple versions of classic arcade games or short Adventures. This one sticks out from the crowd by being a sports game. It's a surprisingly complex ice hockey simulation.
The game lets the players participate in a world cup tournament. The number of players is only limited by the number of participating teams, and the computer takes over the rest of them. There are quite a few settings, like for example the match length, number of players and level of active rules. This way, Karamalz Cup can serve both as a pure action game as well as a more 'realistic' simulation.
The matches itself are show from the side. Controls are perfectly intuitive. What's a bit special (not in a bad way) is that the human controls one specific player of his team, not always the one nearest to the puck. Thus, if another player of the human's team has it, the fire button triggers a pass.
The downside is that the gameplay isn't all that fine-tuned. It's often hardly visible where the puck is (a problem many ice hockey games have), and strategic playing is quite hard and also hardly necessary. Usually, one team is in front of the other's goalkeeper in no time, prompting the graphical perspective to change to a frontal view of the goal and the attacking player controlling a crosshair indicating the direction of the upcoming shot while the defending player controls the movements of the goalkeeper. Another special 'event' is fouls: they often result in a violent brawl between two players - which is done interactively (though this isn't really comparable to a dedicated beat 'em up game, of course).
Ads are restricted to Karamalz apparantely being the only sponsor in the arenas. Gameplay, in spite of the quirks described earlier, is surprisingly good for a promotional game. So, keeping in mind that this is freeware, you can't really go wrong with this one, if you keep the expectations low.