Something where the game mode and start speed can be selected

This will probably boost performance.
probably.

When blocks are too fast, they glitch through everything and sometimes even through the floor.

Best fix would be that they just don't glitch through stuff anymore. Something like 'if they die, they go up like a bubble', meaning they go one block up as long as there is a block being in the same place as them.

I don't want the game to slow down when the laptop is a potato. Only fps drops should be allowed.

Y'know the game mode where you start out with randomly generated blocks

self-upgrading of course.
Oh and it shouldn't update if the .git folder is there.
Oh and there should be a command line argument (-U, --update) that tells the game to only update itself.

Beeklaus why not.

as in "split screen"

Textures for buttons, ect.

can't be that hard.

Still waiting for easyaudi to arrive at v1.0...

Because the debug argument should come after the help argument, but before all the other arguments.
And the update argument should come after help and debug but before anything else.

could be done by checking if there are no collisions if the block is moved one block down, left or right. Not top, that could get abused.

Because that's what real heroes do!