Tried the new version. A few things to note:
1º) In the Lunar Shield game it feels somewhat cheap that the asteroids appear in the middle of the field. The difficulty of it is fine, but it feels like the asteroids should spawn outside of the field and approach at different speed to get the same effect as the current implementation.
2º) I think there is a very small bug where the math questions do not hide the answer behind the explanation. In the Count game, question marks appear while the explanation is up. This does not happen for the math question game.
The more I play it, the more I hate the Flap one. I think my main problem is that it starts somewhat unexpectedly and the birds just goes down like a stone. I would change it so that the bird flies at that constant height until you press a button and then it has that falling behaviour. Another idea is to change this whole game so that it stays always at a constant height and you can change that height with the up/down arrows. I get that it would get too similar to the car one and maybe it's just me and I need to Git Gud, but maybe something to have in mind in case more people complain.
I like the effect when "getting hit", hate the static one. IMO, leave them as they are, I can always go in the options menu to change them (Maybe have a small message upon loading indicating that it is an option?)