Thanks for the suggestions.
We feel that a big part of the game is that you are not sure what upgrades you are going to get each time you play, making each game different than the last.
If we gave the player more control over that, that would - as you say - change the game quite a bit.
We may include something like this at some time in the future, but right now we have no such plans.
So for now, I am happy you like the game as it is.
And of course feel free to give us any other feedback and suggestions.
While we cannot promise anything, we do care a lot about what our players think, and would love to work on features our players want in the future, if we can.