You absolutely nailed the game feel for this platformer, the platforming controls are so good---they give me Celeste vibes! I also like how certain components of the game, like jumping over flags with small counts, makes you actually think about what you're doing too.
I would honestly say the only kind of critique I have is I just wish that there were more interactions that made you think other than the flag-avoiding. The countdown mechanic sort of does, but honestly, not much. And, I get the game is primarily platforming focused, but I think one or two more concepts similar to the flag-avoiding would really propel this game from a platformer that just feels good into a game so good you simply can't forget about it.
Overall, great work, also wanted to mention the overall polish for the game is wonderful too :)