You might want to adjust the scoring.
A simple system would be something like: - accuracy is most important - if tied on accuracy (ie both got 8/10) then tie break is done on speed
In general, across a lot of games - winning is a big determinant in who comes back. Right now it might be very difficult to beat JEV with the way your scoring is setup.
For my game in particular it's like a 47% chance that a winning player returns versus just 10% for non-winners.
Each game mode tests different things. Sprint is all about speed, it will be hard to beat JEV if he doesnt fail but one failure adds 15s. So you have a chance (in fact JEV gets around 80% right)
Versus Measures accuracy but under time pressure, if you score more than Jev you will win.
And streak is also accuracy.
This quiz game, is supposed to visualize how good and bad these type of models are. They can be very fast but they can also fail 20% of the times. As a human, can you beat that?