I have no problems running Ruff'n'Tumble on my A1200 as long as I use TUDE to go to 1.3 rom and ECS graphics.
I mostly played P.P. Hammer on the C64, thought the Amiga version though it looked better and had far less bugs (chances on the C64 were that if you got killed one place and tried the level again the enemy who killed you would not be there)
As for rainbow islands, I didn't think it was that superb a conversion. The game itself is superb but the conversion I thought just lacked something, just like I was missing something from bubble bobble.