EDIT: I have finished the game and updated the review accordingly.

Yooka-Laylee and the Impossible Lair is not only the best platformer I ever played, but best game I ever played period. The levels are well crafted masterpieces with a beautiful soundtrack. The controls are about as tight as a platformer can get. The collectibles have a lot more use than just marking your save file as 100%, with all of them serving some sort of purpose.

Hands down the coolest part of the game is the overworld. Not only does it behave like a light Zelda dungeon complete with puzzles and backtracking, but the stuff you do in the overworld can directly affect the levels themselves! For example, freezing a lake in the overworld will transform a water level into a snow level. And there is a level that you can play forwards or backwards depending on the direction you enter the level from. There is even a level that you can flip upside down! Don't like that the overworld makes it a little inconvenient to pick a level to play? No problem, you can directly teleport to any unlocked level by selecting it on the map. Even then, the overworld is filled with shortcuts that make traversing it easy.

The tonic system is basically this game's way of adjusting the game's difficulty. Positive tonics can make the game easier but lower your quill count (making it harder to buy more tonics), harder tonics make the quill count higher, and there are a plethora of completely useless tonics only there for stupid gags and challenge run YouTube channels. It is up to you which ones to use. It is a shame that you can't use them in the Impossible Lair though.

I also think that there are far too many useless "for fun" tonics. I am fine with the idea of them, but it feels like that most of the tonics you find fall into this category, which made discovering them feel disappointing.

The Impossible Lair itself has been pretty controversial, and I understand why. It's a very hard endurance level that is 20-25 minutes long with no checkpoints. But to be honest, I loved the level. It has some of the most enjoyable platforming sections in the game and tests everything that the game has thrown at you throughout the normal levels. It feels like a proper final challenge. I also liked that the bees you collect throughout the levels add more hitpoints for the Impossible Lair, and because you can try the Impossible Lair whenever you want I tried it every once in a while to see how far I can get with my current bee count, kind of like a high score game. I believe that this is how the devs intended for you to tackle the Lair.

Unfortunately the game lacks some polish here and there. I have seen various visual bugs, and there was one time when the level decided to go "screw it" and rescued the bee for me (how you complete a level) despite me not being near it (I was in the middle of a coin challenge behind the bee). Also, the game dynamically loads and unloads stuff outside (and sometimes inside) the camera view, causing occasional stutter when moving about. It's not enough to impact gameplay, but it can be a little distracting and makes the game feel less polished.

All in all, I give Yooka-Laylee and the Impossible Lair a 9.5/10. It's amazing, and while I do have some minor gripes with the game, none of them have negatively impacted gameplay directly. If you are a fan of platformers, especially challenging ones that demand a lot from you, I cannot recommend this game enough.

EDIT: I have finished the game and updated the review accordingly. Yooka-Laylee and the Impossible Lair is not only the best platformer I ever played, but best game I ever played period. The levels are well crafted masterpieces with a beautiful soundtrack. The controls are about as tight as a platformer can get. The collectibles have a lot more use than just marking your save file as 100%, with all of them serving some sort of purpose. Hands down the coolest part of the game is the overworld. Not only does it behave like a light Zelda dungeon complete with puzzles and backtracking, but the stuff you do in the overworld can directly affect the levels themselves! For example, freezing a lake in the overworld will transform a water level into a snow level. And there is a level that you can play forwards or backwards depending on the direction you enter the level from. There is even a level that you can flip upside down! Don't like that the overworld makes it a little inconvenient to pick a level to play? No problem, you can directly teleport to any unlocked level by selecting it on the map. Even then, the overworld is filled with shortcuts that make traversing it easy. The tonic system is basically this game's way of adjusting the game's difficulty. Positive tonics can make the game easier but lower your quill count (making it harder to buy more tonics), harder tonics make the quill count higher, and there are a plethora of completely useless tonics only there for stupid gags and challenge run YouTube channels. It is up to you which ones to use. It is a shame that you can't use them in the Impossible Lair though. I also think that there are far too many useless "for fun" tonics. I am fine with the idea of them, but it feels like that most of the tonics you find fall into this category, which made discovering them feel disappointing. The Impossible Lair itself has been pretty controversial, and I understand why. It's a very hard endurance level that is 20-25 minutes long with no checkpoints. But to be honest, I loved the level. It has some of the most enjoyable platforming sections in the game and tests everything that the game has thrown at you throughout the normal levels. It feels like a proper final challenge. I also liked that the bees you collect throughout the levels add more hitpoints for the Impossible Lair, and because you can try the Impossible Lair whenever you want I tried it every once in a while to see how far I can get with my current bee count, kind of like a high score game. I believe that this is how the devs intended for you to tackle the Lair. Unfortunately the game lacks some polish here and there. I have seen various visual bugs, and there was one time when the level decided to go "screw it" and rescued the bee for me (how you complete a level) despite me not being near it (I was in the middle of a coin challenge behind the bee). Also, the game dynamically loads and unloads stuff outside (and sometimes inside) the camera view, causing occasional stutter when moving about. It's not enough to impact gameplay, but it can be a little distracting and makes the game feel less polished. All in all, I give Yooka-Laylee and the Impossible Lair a 9.5/10. It's amazing, and while I do have some minor gripes with the game, none of them have negatively impacted gameplay directly. If you are a fan of platformers, especially challenging ones that demand a lot from you, I cannot recommend this game enough.