My thoughts on the game:

1. The goal of playing is to have fun
2. Fun is had when pushing one's boundaries
3. One pushes one's boundaries by increasing in skill
4. Skill is measured as the ability to perform actions with high precision
5. One increases in skill by adapting in response to feedback
6. Therefore, to maximize fun, we should maximize:
- opportunities to demonstrate skill
- high-quality feedback

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Lazer Feature Wishlist:

1. (!!!) Options for hitsound volume and volume normalization https://github.com/ppy/osu/discussions/18714
- When hitsounds are too quiet, it makes it harder to get feedback on one's tapping rhythm.
- When hitsounds are too loud, it makes it harder to focus on the rhythm of the song.

2. (!!!) A setting for hit object fade out duration (0 = instant fade)
Object fade-out is really distracting and it would be nice to not have to use the "number-as-circle" skin hack for instant fade.

3. UI Nitpicks
- Song preview in song browser should loop to the beginning instead of the preview point when reaching the end of the song (It's annoying listening to the last 10 seconds of a song over and over)
- Add an option to disable the various UI delays/animations

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Some more invasive/out-of-scope things that I think would improve the game:

1. Use PP instead of score for leaderboard rankings https://github.com/ppy/osu/discussions/13024
PP is a more accurate measure of how "impressive" a play is

2. Remove OD, use absolute hit error as a percentage of approach time
Problems with Overall Difficulty (OD) / hit windows:
- The same play can give a different score if the OD is different.
- Because hits can only give one of four arbitrary values (300, 100, 50, 0), there is a significant loss of information.

3. Remove HP Drain / Failure
In my opinion, a player should be allowed to play a map to completion and have their score recorded even if the map is above their skill level.

4. Add other opportunities to demonstrate skill
- Accuracy for slider heads (already in lazer)
- Accuracy for slider ends (like mania)
- Make unnecessary clicks count as misses
- Add scoring for positional error, not just whether the the cursor is inside or outside the circle