note: for point 3, this is probably the hardest point to get right. Forcing sections can decrease speedrun appeal, bad placement of stars can cause confusion or backtracking, and overall it matters much more to get points 1) and 2) down before focusing on 3). Hope this helps! Good luck track making!

3) Spacing of stars. Some lengthier tracks have 1 star throughout the whole thing. This is alright, but having multiple stars can increase gameplay variety (by forcing certain parts of the track) and it can make the player much better aware of progression. Example: if you include a star for every 20 second segment of your level, the player may be more keen on continuing until the last star, where they may have not if the track gave them no feedback in terms of progress.

2) Good use of checkpoints. Depending on the length of your track, checkpoints may make the player much more willing to complete it. If a player doesn't complete your track, they're quite unlikely to enjoy it and review favourably, even if the track was good in other regards.

Make a track that is fun first and foremost. How to do this? 1) Have gameplay variety. Example of bad gameplay variety: linear "smooth jumps" track. Example of good gameplay variety: tracks that force you to use breaks (like with ceilings), tracks which use z (could have overlapping paths), and generally, tracks that have areas that the player can fail and areas they can optimize.