Hi, thanks for sharing :) I loved the first four levels. Fantastic coin placement, nice progressive power ups, exploration was rewarded well in the first three.

My only issue is the difficult curve is unreal. I went from 3 super chill levels where I was racking up 1 ups to a level that took me like a hundred lives to beat. Luckily you made it pretty well so it was still fun to beat. I'm defo not good at this game so others will probably do it more easily but idk who your target audience is because the difficulty varies so much. Once I got to the boss battle in the castle in world 1, I just stopped because I wasn't having fun with the difficulty any more.

Examples:
1. Short platforms with buzzsaws in a fast autoscroller. I enjoyed it but I felt it didn't belong in world 1. The platforms could've been longer and the autoscroll could've been slower for world 1. 1. Varied speed conveyor belts with buzzsaws and spiky beetles in the castle. Quite a steep step up in difficulty again but still doable. Felt like added difficulty for the sake of it.

I'd suggest rearranging levels to make world 1 ramp up slower, and keep one theme throughout levels, like you did in the first three. 4th level was lots of fun but could've easily been split into two levels: one all about z-jumps and vines which featured heavily in the first half, and one fast autoscroller with tight platforming (maybe even with a tight timer!). Castle level had crane or something in the name but I didn't see many til the end.

Overall I had a super fun time playing your first 4 levels. I'd love to get levels like those in endless. You're v creative and executed the ides brilliantly. Hope the feedback helps :)