I think you managed to reproduce the original (the early one in the video) version pretty well so good work 
I have no idea what controls it had though, maybe it shot the bullets itself and you used the mouse to rotate? It seems the rotation is not fixed speed in his video.
The game itself is quite playable, although gets quite irritating quite quickly (if there were harder levels, I'd cry). It's hard to remember which colours you can hit.
It's a good training for memorizing RGB though.
I already remember it a little better just because I wrote this game.
And there is nothing past level 3, it's all the same after 3 rings and there's no speed up or anything.
If you're not unlucky and heartbreak yourself accidentally at start of a level when the heart is small you can go indefinitely.
I don't know what "too ambitious" is 
Why did you cut ideas? Is it just because it was a quick version of someone else's idea or because you don't have the time? 
In the end I just wanted to get it to playable state and 'shipped' quickly.
I have the time I guess (it didn't take a long time to write, it's a jam level game), but not the will.
I'm not exactly the most dedicated person.
Arcade style games are not exactly interesting to me either, but it was a nice day or two of coding and small enough to be doable for me, a bit like a self test to see if I can do a game if it's small enough because I keep making demos, help libs or proofs of concept and scraping them because I'm just a programmer and a very bad artist and game designer.
And if I added anything that required something else than SFML I'd have to set up windows and all dev tools on it to compile a windows exe. As it is now, anyone who has SFML can easily compile this on their own.
Although music, xml saves, settings and color modes (via pugi drop in source), sounds, menus, particles, cheats (to debug the game) and so on were all possible with just SFML. But I lost the will and was adding stuff to the todo list quicker than I was getting it done so...
I actually had saves, a simple menu and different color modes already but deleted them (I have a copy of it in case I need it of course).
I might update it, maybe even in next few days or someday when I feel bored, but then again, I might not...
