I found this website helpful for looking at level maps and planning my route through the levels. Just click on the right hand side of the page to change zone.
http://soniczone0.com/games/sonic2/emeraldhill/Also these were my times, I got these times after studying the level maps.
Emerald Hill Act 1:
0.29Emerald Hill Act 2:
0.59Chemical Plant Act 1:
0.44Chemical Plant Act 2:
1.50Aquatic Ruin Act 1:
0.50Aquatic Ruin Act 2:
1.25Casino Night Act 1:
1.18Casino Night Act 2:
2.12Hill Top Zone Act 1:
1.53Hill Top Zone Act 2:
2.11Mystic Cave Act 1:
1.20Mystic Cave Act 2:
1.35Oil Ocean Zone Act 1:
2.21Oil Ocean Zone Act 2:
1.48Metropolis Zone Act 1:
2.27Metropolis Zone Act 2:
2.38Metropolis Zone Act 3:
3.32Sky Chase Zone:
2.07Wing Fortress Zone:
4.05 - including the time taken to get into space.
Death Egg Zone:
4.22 - timed up until Sonic jumps off the Death Egg.
Total:
40.06Allow a bit more time for the 10-15 secs used at the end of each level to display the score. Only 17 levels have results, the last 3 don't have results. 17 x 15 secs = 4 mins 15 secs.