The game actually turned out as I envisioned it. I see it as a solid concept for a rhythm game.
Video with me playing the 2 hardest songs so far:
The game has a lot of freedom in where notes can be positioned. Not as much as you might expect though: you can only have horizontal or vertical lines, and, due to how the information is stored, you can't have horizontal lines unless they connect to the note in another column. That's not something I'm going to add in either, unless I completely remake the game. The game and the editor were relatively simple to make specifically because everything was based on the fact that you only need to know the note timings and the columns, and the program will know where to draw the lines. I could maybe add in diagonal lines, but it'd be tough, and I think the game is fine as it is.
The freedom that the game does have in note placement is good and bad. It's easy to make a bad chart (have the lines go off the screen or the lines intersect confusingly or go through notes you don't actually hit, etc etc...), but you can also create interesting and challenging patterns, or patterns that are specific to the song. It can be fun just watching the notes move around, especially on a song like Drum Lines with 4 different simultaneous beats all having notes to go with them.
I changed the scoring. I knew the old scoring was putting an emphasis on hitting notes, but I didn't realize until I played it how much I personally disliked that type of scoring. So, being my game, I dropped the point values for the middle ranges, so you can miss a few more notes but get a better score if you did a lot better with your accuracy in general.