Well done for your first jam! Liked the concept, however, I felt like I couldn't shoot enough to dissipate the heat generated. Like the other comments are saying, only being able to shoot in the direction you're moving is quite limiting.
Another improvement could be made in the background. Due to it being static and the ship always being around the center of the screen, it sometimes felt like there was no movement. Some background elements like planets or suns could alleviate this.