First, let's look at the actual meaning of the attack:
気 comes from "spirit", "soul", "energy" or "air".
功 means "cultivation", "control", "technique", "ability".
Combined we come to something like "Spirit Control", like the Chinese Qigong.
The last kanji 砲 means gun or cannon. So let's go with a "Spirit Control Cannon". However, the English dub and video games went with the unrelated term "Tri Beam" triggering mistranslations and inconsistency with the German attack name.
The German manga and anime went with term "Kiku-Kanone" during it's adaptation in the late 90s and early 2000s. The decision to partially keep the Japanese term is nothing new, as it keeps a part of the original taste and through keeping "Kanone" as "cannon" (砲) it's makes it a fancy and unique attack name. Why 功 (こう) was changed too く("ku") I don't know, but it's not too far off, since it's also an alternate reading for the kanji. Maybe a translator's choice as it sounds better in combination with the "Kanone" suffix.
Anyway, so the term "Kiku-Kanone" is THE term Germans fans relate to 気功砲. But the German translation in the video games failed to keep it consistent following the anime term. While the Budokai series used "Ki-Explosionskanone" seemingly another translation attempt from the Japanese original, the translation of 新気功砲 made the following translation even weirder.新気功砲 (しんきこうほう), so just the Kikoho with a "Shin" (新) meaning "new". The English dub uses "Neo" same as the German dub making it the "Neo Tri Beam" or "Neo-Kiku-Kanone".
However, the games went a different path in German: "Dreifacher Neostrahl". So literally "three times Neo beam". And seemingly the normal 気功砲 was changed to "Dreifacher Strahl" ('just' a "three times beam") is recent games like Xenoverse or Legends.
It all looks like a straight translation from the English without knowing the background of the attack. That's why I was still ok with the "Ki-Explosionskanone" in older games even though it was not consistent to the TV show.
Following that pattern 魂の気功砲 (Tamashi no Kikouhou) also received an interesting localization: "Dreifacher Geisterstrahl" ("three times ghost beam"). As this one-handed variation received its first official naming as late as in the "Raging Blast" game, there is seemingly no localized anime or manga term. A consistent localized German term would be like: "Geister-Kiku-Kanone", "Seelen-Kiku-Kanone" or keeping the Japanese with "Tamashi-Kiku-Kanone".
All these mistranslations are missing the fact the Kikouhou is the actually attack and terms like 魂 or 新 are just additions making it another variation of the attack.
Going through recent games you see a few more of this consistency problems, but the 気功砲 is a good example for what could went wrong and "get lost in translation".
Anyway, as Dragon Ball will remain for many, many years, there's still hope new games will keep their terms consistent at some point - sooner or later - with game companies and the local anime and manga translators working together...
