Nice game tomcat, very polished. It's like something I'd expect to see in an arcade of my childhood
I'd guess the Amiga would be able to handle this no problem, even if you did it in C++ and ran it under the OS without hardware sprites. There's not really very much going on on-screen at all.
RE: sprites - you'd be limited to 4 or 16 colours and 8 or 4 objects on screen at once respectively, unless you got clever with copperlists and even then there would be situations where you would need to fall back to a bob system. Also the graphics formats for sprites and bobs are different so you'd need two sets or some code to dynamically convert (and cache?) them.
So given that you don't have much moving about and the fact that you'd need to implement a bob system anyway, I'd go for bobs alone to keep it simple. If it's too slow then you can think about dropping in some asm code, using sprites or whatever. Make it work, THEN make it fast
FWIW Uridium 2 uses a combo sprite and bob system, but theres a helluva lot more screen movement in that than PPP
BTW what's this "Way Of The Hubba" ?