Following an approach to Runway 09 the aircraft floated along the runway and the pilot decided to go around. He reported that, as the aircraft was climbing through approximately 200 ft agl, the engine stopped, re-started and stopped again. Power was restored once more, but only briefly, and the pilot decided to land in a field approximately 1.5 to 2 nm northeast of the runway. The approach was uneventful but, as the aircraft slowed after touchdown, the nose landing gear leg collapsed. The two occupants were unhurt and vacated the aircraft through the normal exits. The cause of the engine failure was not determined.