BEFORE YOU POINT OUT MY TIME PLAYED: I've played much more of this game on a tablet. My review for the PC version will be based on the difference in playability between the two. I've played enough to come to a conclusion about that.
Frederic: Resurrection of Music is a rhythm game where you catch falling notes onto piano keys at the bottom of the screen. Think of Beatmania without the turn table, and you've basically got it. The timing for a perfect hit takes a little getting used to, because it's relative to the center of the actual key on the piano itself. Since a black key is much shorter than a white key, a perfect hit on a black note will be higher up on the board than a white note. Otherwise it's fairly simple, with normal notes, hold notes, and swipe notes where you move across as you hit a key (more on that later). The note patterns are fairly good, and fit the pace of the songs. The music is all Chopin compositions redone in various contemporary music styles. The songs are...alright. The western themed one is pretty terrible, but they're all still recognizable as Chopin. It's also worth saying that the story is absolutely insane. Nothing makes sense and it's pretty great.
First and foremost, this is a game meant for tablets. There have been tablet games that have made the jump to steam with varying amounts of success, but Frederic is absolutely designed for a multitouch screen. Before you even boot the game up, it asks if you want to launch the touchscreen version instead. To get around most people not being able to touch their monitors to make things happen, you're given two other control styles that you can mix and match as you want; keyboard and mouse. Keyboard sounds like it would make sense, since you're emulating touching keys on a piano, but it never actually feels right. You can reconfigure the keys to anything you want (except for the space bar, which is reserved for using a special move), but it's still just not a very natural feel. You could probably get somewhat used to it with enough times, but remember, the timing on a perfect black note is different than a perfect white note. So, every other finger has to hit a note slightly earlier than the others.
Remember how I mentioned slide notes? They're meant for you to touch the key and then swipe your finger across the piano. You can't do this with a keyboard, naturally, so those are some points you're just not going to be able to get. Now, you can use a mouse instead and just click the keys, which will allow you to hit slide notes. But then you have some hold notes that continue as other notes are coming down, since it was made with multitouch in mind, which makes the mouse not ideal for that situation. Then there are bonus golden notes that fly up from the piano for extra points. On the tablet, you just tap the note to get them. On the PC, you could click on it with the mouse, but if you're using the mouse to play then you're probably too busy hitting other notes or holding a hold note to go click it. You can also collect those notes by pressing a key on the keyboard, but that key is random each time. So have fun with that.
If you have a tablet or a good phone, I would definitely recommend getting Frederic there if you're a rhythm game fan. It's definitely the way the game is meant to be played and works just fine there. There are two bonus levels in that version that are locked behind DLC (as opposed to this Steam version which has them for free as unlockables), but the bonus levels only cost a dollar total and the base game itself is $2. It's the way the game was meant to be played, and you're just going to get a subpar and sometimes frustrating experience on the PC.
Now, there are two reasons why you might actually want to get the Steam version. If you DO have a touchscreen of some sort for your computer (or if you're using a Surface or something), then you can play the game the way it's supposed to be played and it will work just fine. You would be paying $3 more compared to an app store version, but you do get the soundtrack as an extra if you really want that. The other reason may be if you have a Beatmania controller you can plug into your computer. The keys on the controller match up to the keys in game, so that might actually be kinda cool. Unfortunately, you still won't be able to do slide notes, and unless you play it one handed you're definitely not going to get any bonus gold notes. It's enough of a novelty though that it might be worth playing with.
If neither of these conditions apply to you, then don't bother getting Frederic on Steam. It's just not the way this game is supposed to be played.