Timeless

Nice work! I really think this game has some strong aspects and has room for improvement.

Let me start with the outstanding features of the game:

• Engaging and progressive storyline, easy to catch on and follow. The cinematics are short and easy to understand, the notes give interesting details and leave room for more to come
• Sound design is perfect (or at least better than most indie games). Every action gives audio feedback and I can see that you really spent some time on it. 
• Great enemy design. The "silly" design of the enemies works really nicely with the games aesthetic.
• KISS (Keep It Simple Stupid) design. I don't think anyone will have any problems understanding the mechanics. The mechanics are simple and fun and that is just perfect. It was really fun for me to stop the time and circle around the enemies while throwing banans.
• Relating to the last point, the UI is also well made, it's kept simple without troubling the player with many elements. Also I like the UI animations, small details that give the feel of a completed game. Also I was wondering why didn't you put the watch timer directly on the watch screen.

Music

If you were going for the calm / chill vibe it works perfectly. It's great for a fun game like this one and does not distract the player. 

But if you would have prefered going for a more action fast-paced gameplay then it doesn't fit. This is the case for the bosses where the music doesn't really cope with the gameplay.

What can be improved / changed

• Level Design. Following the signs is an easy and intuitive way for the player. Also I think this really works with the story, because the writer wants you to follow the rules. But what if you don't? Well the writer doesn't care at all, so breaking the rules has no effect. Now what if the rules were actually strict and the writer doesn't want you to break them. Well, just add an invisible electricity wall that damages you when you get close. This way you solve one critical issue that happened to me. You have to acknowledge the fact that players, generally, don't like to follow rules, they like to break the game. And that's what I did. I just took another route. Of course this means that I didn't take the notes in order and had to come back for some of them. You can see how this kind of ruins the whole game progression. Ok, for a small game like this maybe this doesn't matter too much, but it's an improvement that makes a big difference on how players see your game. Also some levels can be open (like the bridge one), but don't leave the player confused.
• Combat. I don't know how many people playtested the game before release, but for me at least, the combat isn't always great:
• Enemies HP. It becomes frustrating. All enemies have a lot of hp. In most shooter games there is the low hp enemies which you can basically one shot, and the high hp enemies which are less frequent. But here there are no low hp enemies. I think there should be a balance, otherwise the gameplay just becomes repetitive. In most cases I didn't even bother killing them anymore because when you have 3 enemies following you it will take you over 20 seconds to kill them. This is just not fair for the player so he will just run away. A simple fix for this would be to split a level in areas which will be locked once you enter (invisible / electrical walls). To progress you have to kill all enemies. This also helps with the level design. When you let the player wander around, most of the times he will just ignore the enemies. Another suggeston I got is to make smaller variants of the current enemies. For example the flying-eye can have a smaller variant which can be killed quickly in 1-2 seconds. Then just pair the smaller flying-eyes with the big ones. Edit: I realised that the bananas actually do a lot of damage, I was not using them very often. But still, when fighting multiple enemies you won't have enough bananas.
• The Laser. The major flaw I noticed at the first moment is that there is absolutely no visual indicator for dealing damage. This adds to my other point, and makes it even more annoying to fight enemies. My suggestion is to either add a hp bar above the enemy, but this can clutter the screen too much, or change the enemies color as he is damaged. Secondly the laser cooldown is inneficient, you can just spam click and it works the same, so it doesn't stop you from defending yourself. It's like in a game where you have stamina, if it reaches 0 and then just goes back to 0.01, you can start sprinting again. Of course this means that you can basically sprint for as long as you want. To avoid this problems just add a recharge cooldown. When it reaches 0%, before using it again you will have to wait until it recharges to 20%.
• Stop Time Watch. This mechanic improves the whole gameplay. The cooldown has the same problem as the laser. When I was playing the game I just spammed Q and Left Click and I was invincible. That's what I did for the last boss fight. I didn't bother killing any enemies around me, just spammed until the boss was dead (oh and also why not adding a boss hp bar). Anyway, this mechanic was a lot of fun, like I said, stopping the time and throwing bananas while circling enemies was great. But I felt like there could be more than just this. Like imagine enemies coming from all directions circling you. You stop the time and throw bananas to kill all of them. Events like this would be really fun, but here comes the problem with the enemy hp, you can't fight more than one enemy at a time since they have too much hp.

Overall something the game needs is more playtesting if you want to make it perfect. Right now it's a fun game and most people can enjoy it as it is. But some might stop playing in the first minutes because of the overall design. Keep the game simple as it is, I am not saying you have to over-complicate it to make it fit for everyone. If the game is simple, the design has to also be simple. That means it should always be clear what you should do and what you shouldn't do.

I hope that some things that I said here will help you. Also some things I said might just be my opinion and maybe you have a different point of view, that's why you need a lot more feedback before deciding on what to change. It is up to you if you want to further improve this game or work on a new project. But at least keep in mind what can be improved for your next project if not for this one.