Hello, I thank you for your detailed advice, it is quite rare and very valuable for a beginner like me. And more from a professional : )
I should probably learn phaser.js, for now I like to be able to understand what I'm doing and how my game works in depth, but for jams it makes me very slow...
I had put margins in the generation of the position in abcyss of my items, I must have missed something. I'll fix it, thanks for the warning!
For the gameplay I agree, there is something missing. I had some ideas but I didn't have enough time. I'm very afraid to add concepts that would make the gameplay unclear or too complicated, I hope that with practice I will be able to estimate the value of an idea and what it implies.
Small question, I've already seen the assets of your game and I like them, where can I get access to them ?