3 classic games in one? What a deal!
Even though the picture is crystal clear, it is obvious that it cannot be anywhere near the PS3 standards, so it can look relatively terrible at some parts, but that shouldn't get in the way of enjoying these great games.
You play as an agile prince with a set of cool acrobatic moves and powers to control time. The PoP series was always focused on platforming, so be ready to climb a lot of ledges and jump across plenty of gaps.
The Sands of Time had an issue for me though, the voices weren't loud enough so it was hard to hear any of the dialogues, even messing in the audio options didn't seem to help, so you might be switching the volume up and down frequently. Don't let that stop you from playing this great game though. The level design is great and the story drags you in. The combat is really unique as you pull off wall runs and turn back time to undo mistakes, but it can get pretty repetitive since there are way to many incoming enemy waves and all they do is just stand there and look at you most of the time.
Warrior Within takes a more serious approach as the prince grows older, the game becomes more darker and violent. The combat also gets more deep with some combos to pull off, as well as use secondary weapons to dual wield. Once killed, each enemy will drop it's weapon for you to pick up, those weapons will have limited durability, can be thrown and other enemies or simply used to execute powerful attacks. The level design now follows a more hub based system, where all of the areas are connected to a single point in which you can chose where to go to complete your task, that means you will find yourself in the same area many times and possibly even get lost if you don't pay enough attention.
The Two Thrones is the final chapter in the Sands of Time trilogy which has a fresh twist to the series as it focuses more on stealth rather than head on combat. By sneaking up on patrolling guards you can initiate speed kills that let you take enemies down fast with only a few inputs.
Make no mistake, all 3 of these titles are great and are not worth missing out on, but the HD port does seem to have some audio and video issues. While the picture is crystal clear, it reveals some irregularities with models and textures. However none of this should get in your way of enjoyment if you prefer good gameplay instead of groundbreaking visuals.