Thanks for trying it out again! Unfortunately, the visual effects graphs we used in Unity are unsupported by WebGL and won't be feasible at all until WebGPU is developed (something like years away), so you miss out on exactly the feedback you mentioned (railgun firing visual, sand kickup, boost smoke, explosion when killing an enemy) when playing it in the browser. They do work in the .exe though!
Not sure we will do anything to address it in the polish phase, we would need to make hard modeled visuals instead and use some other system to get them to display, and the HTML5 version is mostly an easy way to get exposed to the game rather than the intended way (it has other limitations too).
You're correct about the drift (spacebar) making you turn faster! It halves your max velocity, doubles your max angular velocity, and decreases angular drag so you can get a sharper turn. The sand kick up happens all the time but you can really see it when doing a drift. I might do something like add a couple extra dust emitters that activate only when you drift so it really kicks up some dirt.
We'll try to look into the sand shader again to address the reflection on the dark side, thanks for the feedback.
Multiplayer unfortunately is still not really where we would want it to be and we plan to focus on that mostly this week. You can join a lobby together but non-hosts (it seems) are really wobbly unless they mount a turret and there isn't much that is synced between players besides the ships (you can't see other players for some reason, you can't see them shooting sometimes, enemy health and position is not the same). But you can get in a lobby together and ride around in the ship while someone else drives!