Firstable, not all mentioned games are better on the CPC. Target Renegade is cleary better on the C64. Rick Dangerous, Shinobi and Batman got proper C64 conversions. Games like Dragon Ninja, Afterburner, Total Recall, Robocop are crappy 8bit games/8bit ports. No matter what 8bit platform.
The c64 has the speed, but no colors to do arcade games, that's why all the games i cited above are better on CPC.
You sound like a broken record. Colors = better game? Come on, matey. This is ridiculous. The CPC has no hardware scrolling, no highres sprites and a weak soundchip. A great handicap, if you want to produce quality Arcade games. Though the later CPC Plus/Amstrad GX4000 were a nice machines.