This one's based on Nesica X Live arcade version similar to what Ikaruga was ported to Steam based on that as well. Ikaruga for Nesica X Live and Steam has additional enhancements as seen in Chapters 3 and 5 as well as the re-changed Game Start screen and the achievements. Crimzon Clover on Nesica X Live has the achievements, improved graphics in HD with newer sprites, as well as new music that isn't heard in the original version when in Unlimited Mode. Other major changes include the game ending, the UI as well as the new fresh Game Start and Title screens. The game ending surely has the simple 3D plane of the sea with some fog effect but other than those simple 3D graphics, the rest is 2D. And of course, the sound effects are changed as well as if the game is going beyond the doujin game quality.
The Steam version has the Training Mode as well as the Novice Mode and other stuffs that are beginner friendly and is based on Nesica X Live version. The trailer was first seen at Stunfest which was the shmup related event that already took place before it was made available for online public viewing via Steam client/website. Lastly, the game resolution. I don't know what the configurations for game resolution are like.
The Steam version of Crimzon Clover will be released sometime in June and be on the lookout for idiotic reviewers out there. We had already seen one doing such a bad review on Ikaruga Steam version and it looked like we might have hated that video.