High level go-arounds frequently present challenges that are unexpected and, usually, unbriefed for. In the sim it always seemed to be a g/a from minima. Fortunately some instructors had greater imagination. I distinctly remember one extremely straightforward ATC instruction to "go-around and climb straight ahead to 3000ft". Desperately simple eh??... Except that we were already at 3400ft (no a/p) - and managed to climb to 4k before we sorted it out. Lesson learnt. A proper, thorough - and varied - brief is an excellent in-flight safety strategy.