Hey, thanks so much for playing and for the thorough review!
And as for your comments:
1. Some way to at least "scry" and see whether an effect will be positive or negative (if not directly choosing it) in exchange for some cost could potentially be neat, yeah.
2. Orientation is always negative, yes. I don't think there'd be a feasible way to do different levels of it (rotated 90 degrees would be a nightmare). Giving it a chance to have no effect would make it more of a gamble, but that also would mean that some of the time the card does just 2 things, which is less interesting to have to deal with.
3. I completely agree that the game needs to communicate what's going on to the player better. We ended up running short on time to add polish like that in the jam, but if we ever revisit this we definitely plan to have a visual indicator for when bullets reach the end of their range, and to have a much fancier and more clear ending. Also telling the playing whether each modifier turned out to be positive or negative would be nice.
4. Yep, the length (or lack thereof) is also a result of time pressure. We'd definitely have liked to have an expanded main mode and maybe even a endless variant.
5. Yeah, regardless how we convey it some form of HP indicator would be important. Personally I think a meter of some sort is easier to read in a bullet hell context than character sprite detail, but having injuries in addition could be a nice touch.
6. Well, you can thank @MantaRay for the music! :P