I've never really made it much past the Turbo Tunnel in the past, but I recently got an Everdrive N8 Pro, largely because I wanted to have more than 1 save state slot to practice. Since then I've been grinding at the game hardcore, got a save state at the beginning of each level and just practiced each one over and over again.
At this point I can get from the beginning to Clinger Winger (11) on the original cartridge without using a continue, so I guess the Clinger Winger grind begins. The level is just so boring to me, hard to stay motivated about pressing the dpad perfectly for a couple minutes in a row.
I must say though, the game is actually really fun. Beating it comes down to a lot of memorization, but there's enough skill and dexterity involved that it's still quite challenging.
Hopefully I'll get the last 2 stages practiced soon and I'll be able to finally beat this beast. I've seen some posts online suggesting that you pause when coming to a turn to buffer the new input, but that still means you have to pause at the right time. This one's going to be a challenge I'm sure. I feel like the final level will be easier than Clinger for me.