I had a go at BMX Trial: Alex Kidd... it's quite hard due to the paddle controls and large, wrapping area, and I think the level exits probably need to be labelled too. But it's pretty easy to map otherwise.
Edit: another one, but unaligned and with no Alex sprite. Using these hacks:
; BMX Trial: Alex Kidd
; Mapping
[crc32: f9dbb533]
; Infinite energy
ROM[1078]=0,0,0
; Disable water animation
ROM[EA2]=0 ; tile animation
ROM[EA7]=0
ROM[d3d]=c9 ; palette animation
ROM[1039]=c9 ; whirlpool animation
; stop the clock
ROM[10be]=c9
; infinite jet bike
ROM[19a7]=0
; set c410 = 1 to enable, 0 to end