I think your wrong on that score, various polls in the past have shown that most people have 030's and AGA. Really you shouldn't need more than an A1200 for a zelda clone.
Yeah, I have had a Phase V 50mhz 030 since the 90's and while some people have 68040's and 68060's, they are in the minority.
If I was going to spent time writing software I'd want the most people to be able to run it. So I'd be looking to support as slow a machine as possible. Some people are targetting WinUAE users, but that just seems a little pointless.
It might not be possible to make it fast enough on an A1200 with just a ram expansion, but indivision 020 & 030 accelerators are the only ones available now.