I wondered about the reduction in controls and therefore gameplay (from the text) .?. I don't know who this is for :D
I did notice you can shoot through your own defenses, something that was not part of the original idea, and which makes the game easier.
I see this as a remix for the remix generation. Give it a go, I guess? :)
Viewing post in Space Invaders One Button (C64) comments
It's an accessibility version, but also just a fun way to play it. It's much easier like this on a touch-screen device. Luca kindly gave me permission to mirror it here: https://oneswitch.org.uk/art.php?id=112 - where you can see Colin McDonnell (a switch user) playing one-button / one-switch Dragon's Lair.
Luca's made a brilliant job of this. Wish there were more this good.