A lot of players dislike race mode. While I think it's partly to do with level design, it is also the mechanics;

1. You can keep spamming shots. This makes it more difficult to disperse at the start than it should be. Same with reason 2. However, this can be circumvented with AS.
2. Treasure mode with its additional bad mechanics - Not being able to go on springs while blinking. And the terrible chain-shooting (being able to hit others while blinking). Fortunately the latter won't happen in 5.0 anymore.
3. The weapon balance is bad. Powerups are almost completely useless and toaster is trash.
4. Melee moves are virtually redundant, (unless you're Jazz reaching some high up platform, though if that's the case, the level is unbalanced). This is linked to powerups being useless other than being full ammo boxes, and bad weapon balance. Also, that you have to slow down, and you don't ever want to slow down in such a game mode unless it lets you get ahead. This can be circumvented with level design partly (respawning buttstomp blocks to shortcuts, perhaps? I know that couldn't be utilised back then, but it can now).
5. Once the players reach ahead too much, it's virtually impossible to make a comeback. Some might like this for those who feel entitled to winning, but this isn't the case with other gamemodes. Also, always being ahead peacefully will get boring at some point.

Now for common level design issues in race levels:
1. Too cramped passages. Good luck trying to dodge anything. Unless it's a shortcut in race, it's simply annoying.
2. Unintuitive design. It's simply frustrating losing just because you don't know where the important things are.
3. This reason 90% of players won't care about. Bad character balance. I know it's partly a mechanical issue too, however.
4. Wind... why would you add that in a race? It disrupts the flow or/and exacerbates clusterfights.
5. A single spring dissapearing (for a while) after use. I figure this is only in one level, though it's still annoying, for the same reason I dislike wind in race levels.

I made this because I'd like to make a race pack many players (and me!) can actually enjoy. Though I don't think I'll start working on them until race mode is fixed. I will not use treasure mode for it, as it's complicated and annoying.

Some may find it odd for me to point out flaws rather than say what would make a race level fun, though I can bet once all (or most) of those don't exist, it may actually be enjoyable.

So, what do you think would make a race level fun?