I'm not sure if the Mega Drive was more powerful than the AMIGA? Turrican 3 was one of the few games that looked better on the MD compared to AMIGA.
And Global Gladiaors I think.
Lion Heart on the other hand looks better than anything on the MD.
A lot of AMIGA games used 64 colours using half-bright colours. A careful choice of the palete resulted in a very close 64 colour look like the MD.
I think it was because of disk space.