''Pirates!'' includes a lot of Graphics (Mode 0) and music. The game is notable for being one of the (too) rare 6128 specific game: only disk version and 128KB RAM were supported. In theory, 464 (+ disk drive) and 664 with Extra Ram upgrade should work. (maybe not ?)
This port of ''Pirates!'' is also notable for its underlying structure being written in Locomotive BASIC, augmented with machine code routines for graphics, audio, and the arcade portions of the game. Presumably this is largely the same BASIC code as in the C64 version, although on the C64 it is apparently much harder to access than on the CPC (here where the files are not hidden in the catalog and only protected from listing by the standard ",p" BASIC attributeprotected mode).
Despite it's ultimate awesomeness, the Amstrad CPC port was a bit slow and graphics could have been a bit better. They were somewhat obvious as a C64 port in that respect.