Sonic The Hedgehog has a lot of games. And in these games, are boss battles. Boss battles are designed to be a test for the players skills with the game's mechanics, and controls. Games series' like Mega Man and Donkey Kong I believe have perfected this design philosophy. Such as Captain K. Rool, and Shade Man to name a couple examples.

However, with Sonic The Hedgehog, it's always been two sides of a single coin: It's either Case 1: The Boss is too easy and goes out too fast due to Sonic's sheer speed. Or Case 2: This boss is incredibly frustrating I can't even attack half the time due to the boss moving elsewhere.

With that, I've noticed with Sonic Team's bosses implemented within all of Sonic's classic entries, they seem to lean towards Case 1 for the majority of it's bosses. Other developers like Arzest and the team behind Sonic Mania lean a lot more into Case 2 with their entries. From my perspective, it's this swaying pendulum between the two different philosophies that seem to have the need to sacrifice one for the other.

What's the solution? Well, I believe that solution is found within a little game called Sonic 3 and Knuckles, Mushroom Hill Zone Act 2:

Observe the boss mentioned

This particular boss boils down to this: Spin Dash into the Egg Scrambler whilst dodging the logs coming in at a decent speed. There isn't anything halting what Sonic has been doing this entire game. Running. Running and jumping. This boss takes these two common actions taken by the player and makes them the focal point of this boss. Sonic is running at top speed and is not likely to slow down at any point during the fight. There's enough time to react to the spike balls due to the spike ball appearing moments after the intro has ended. And lastly, Sonic looses momentum when striking the boss, leaving a high chance for a sizable amount of time to happen between the strikes.

The only problem to this boss is it's rather short HP bar during the fight. A simple tweak with the amount of HP and you have yourself the perfect boss for Classic Sonic gameplay. It asks of the player to take it's lessons learned throughout and puts them to the test. Without too much spamming of the A button, and doesn't rely on invincibility frames to make sure the fight doesn't end in two seconds.

This has been my Classic Sonic The Hedgehog and Boss Design discussion. This all just my opinion and am by no mean a Classic Sonic Design Master.