Thanks for the comment! Yes, you're right that the boost is the core concept - and since that's the part that hits the "countdown" theme it was the priority to get right during the jam. The gear shifting section is only relevant before the boost starts; the idea is that you want to efficiently shift up to high gear as soon as possible for the launch.
In this version, it's a distance race rather than a time race, so you ideally want to use your full tank of fuel before the boost to maximise your total distance travelled. I think the obvious next step for that system would be to lock out the nitro boost until you reach a certain speed (say, 200 mph) since that would justify needing to climb the gears before the boost.
An idea for that section was to require the player to release the acceleration and move the stick manually (so ⬆️➡️➡️➡️⬆️ to go from 2nd to 3rd, for example) which would add a little more dexterity play it, but I didn't manage to implement that for the deadline. For future versions, I'd also like to experiment with things like hills or rough terrain that would require you to lower your gear temporarily, which would give a lot more interactivity to that initial section.
Of course, after adding all that, the real challenge will be balancing things so that one aspect (like timing the boost well) doesn't just become the only factor that matters! It's a tricky one!