Thanks for such a detailed and valuable response, I really appreciate it!
Moving speed - yes, I noticed it too late that either I should make the level more condensed with shorter corridors or increase the character speed.
The apples are the checkpoints, definitely I should've place them better and make them more obvious. Loosing so much food is frustrating, you're right, I didn't think about that from that persperctive. Checkpoint logic should be revised.
Anyway, you're strong and if you say about 200 then you found the game final goal, congrats! And thanks for playing!