Three karatekas are fighting on the same screen (and the same backdrop), in order to proceed in gaining belts. After gaining some points there are frequently two bonus games where you must either kick bombs away (before they explode) or you can deflect fireballs holding a shield. A second player can join the game as well and the third can be controlled by the CPU. IK+ was one of the best and more fun to play karate games during the 8bits and 16bits home computers era. The GBA (and PlayStation) ports offer the same quality of gameplay which is addictive even with the today's standards! Win points, get the highest belt and be the new master!
The graphics are cute and the character animation is nice and smooth. The GBA port is technically identical to the Amiga and Atari ST versions. Although the background detail does not change, there is a wonderful animated sunset near a temple. There a few short animation found at the background too (birds flying, leafs falling from a tree, fish jumping! etc).
What is really impressive with this game are the sounds FX which were produced using high-quality digitized samples from karate/fighting movies and Bruce Lee-style cries. Unfortunately the GBA port cannot reproduce the quality of awarded music found on the Amiga version (a memorable soundtrack) composed by Dave Lowe and performed several years later at the Symphonic Game Music Concert III in 2005 as well!