Ok, I've downloaded your game, and I'm trying it right now, my review is below.
First Impressions/Menu: My first impression of the game was soured a bit by the fact that it decided to full screen on me right away rather than starting in windowed mode and giving me the option to swap it up. Unfortunately, full screen is a bit obnoxious with my computer as it causes several of my programs to stop responding properly. So, I got into the game, noting the change to the donation screen. In whatever language the preferences.dat file was set to there was no text on that screen other than the accept and later buttons, and after a bit of investigation and messing around I finally got my language changed to English. One thing you may want to note, in windows starting something with ~$ marks it as a protected system file, so not just anyone is going to know how to get rid of that file. I'm not certain if that is temporary, but I also tried both links, one continued into the game silently, the other took me to Wikipedia in my browser and still continued into the game. If you're trying to make your users accept those conditions, I would suggest not allowing them to bypass them like that. So, I got to the main menu, and noted the Sonic and Tails in the airplane in the background and the other airplane thing, you may want to note for future reference that they look very cut out against the rest of the menu background, you may want to consider changing them up a bit. You may also want to consider going to a newer version of the engine to take advantage of a fully scripted main menu, one which you have greater control over, and the new menu song which I absolutely adore.
Opening Cutscene: You have the very first edit I've seen yet to the opening cut-scene, and I'm impressed with how well you handled it considering the way it was created. I saw yet another cutout along the bottom of the screen in the last part of the cut-scene, you may want to fix that in the final version.
Lost Paradise 1: Suddenly, I found myself underwater, and very slow. Your character's max speed is not something I am getting along with at the moment, though I'm not sure it has been edited in the slightest, so I'm going to edit the character template right now and then start up the game again. Either way, I would not suggest starting the character so far under water and I would not suggest putting such a large water section into the first level because water is a fairly difficult obstacle and doesn't allow for a lot of player exploration in your earliest level, the place they're going to be exploring most. Anyway, with my modified speed profile I was easily able to get to the top of the cliff, then after looking around for where to go I decided to go down into the section at the start where you could go down to find secrets in Open Surge's sunshine paradise. I found my way across the lake without too much difficulty, then found your secret ring. I would suggest you either don't put one in or actually make it do something. Now, I went down the cliff and found 2 chaos emerald looking things. I would guess that one was a sign and one was the goal post. You will likely want to edit your sign to be more of a sign and less of a goal replica.
Lost Paradise 2: Now, on to act 2. Act 2 we start out with 2 invincibility boxes, a whole bunch of platforms, and a text box. First of all, I would suggest getting rid of the invincibility boxes and replacing them with 1-2 ten ring boxes, as this is the first boss and rings provide players with more of a 'try again' model that won't have them dying all over the place. Second, I would suggest making all the platforms in the boss arena cloud platforms, this way the player can jump through them from underneath and they won't be a hassle to get up onto. Third, I would suggest getting rid of that message box. It gets in the way a lot of the time, and is really unneeded for the stage. Also, I would suggest giving credit to SilverstepP, as he did write the code for your boss. Because it is 7 am and I don't have the moxie to stay up much later I'm going to look up your quest order and skip the boss as the platforms and lack of rings are making it hard for me to beat in my current state of mind.
Tidal Tempest 1: Tidal Tempest seems to start out very generous with the rings, there is a slope just down from the beginning that doesn't work too well when the red springs toss you into it, I'd suggest looking into that. I'd also suggest changing up the brick-set/music here because that's generally what a new level name signifies. There is a red spring off the ground inside the maze, springs look odd when they aren't attached to anything. By jumping into the side of the big spike pit and continuously jumping upward I was able to glitch through the platform above, you may want to reconsider that trap a little, especially considering exploiting this glitch brought me right to the end of the stage.
Tidal Tempest 2: Tidal Tempest 2 starts up and our heroes are all together, I would suggest a cut-scene at the end of Tidal Tempest 1 at the very least to explain how they got together, but I immediately picked sonic. I ran until I got to the section where you're climbing back and fourth, again I must say that cloud bricks would be much better suited for this area. The two goalposts at the top of the climbing section are redundant, I would suggest just using one or using a custom graphic one that does more along the lines of what you want it to do. Sonic turns into surge whenever he touches a zip-line, that is a little strange and will require you to edit the object to call Sonic's animation frames when the character is Sonic. I got to a section above the opening and near the exit and found a bunch of stacked platforms, may I suggest putting in something other than grass on grass on grass on grass here.
Dark Night 1: I rather enjoy the change in scenery, be sure to give credit to whoever made your brickset/background in your readme/license as well. I got to the maze-like section and found my normal instinct failing me, perhaps coloring the sections you can walk through differently or not putting those bricks there would help to guide your player to know where they can go and where they cannot. Then we get to the red spring right before the blue spring. Pressing the run arrow on this ends up setting the player back, it is not intuitive, perhaps increase the next gap a bit so this jumping doesn't occur. The destrucible section, while interesting, means that if your player goofs up they will lose a life, keep that in mind when designing this or you may end up with a very frustrated player. The blue spring right before the cliff is simply cruel in a game about speed it is not a great idea to put instant death for people who try to use speed. Also, I just noticed, where did sonic suddenly disappear to? On my second run of this level I noticed some of the physics traps I failed to fall into the first time around. Some of these are very glitch ridden, I would suggest thicker platforms and better ways to let your player die once inside than pressing themselves through a floor.
Labyrinth Zone 1: The parallax background on Labyrinth Zone 1 is really cool. Did someone design that for you, or did you do it yourself? Either way, give credit in the credits where it is due. The spikes in this place are very mean, the sides of them hurt you, and they do not have enough room between them for Surge to jump safely as his motion controls are a bit slippery, at least as far as I feel them. I rather enjoy the background, and I rather enjoy the brick-set, but together they can cause the eye to very strange things, and the hurt after the goal post is a bit of a low blow, I'd suggest getting rid of that.
Labyrinth Zone 2: Labyrinth Zone 2 has some very problematic spikes, their hit-box is very strange, and you can be hurt by them from quite some distance away. You provided many many water shields in there to compensate, however I'd suggest fixing your spikes and making many of those shields into bubble spawners.
Cutscene 1: Cutscene 1 didn't really make much sense in context, also I'd suggest having a standard art style when looking at both sonic and surge up close.
Final Boss: Was able to finish it without fighting either boss, make defeating the final boss or 'opening the cage' your level clear reason here and put the cage out of reach until the boss is gone if that's the path you go.
Ending: You did give credit where it was due, I'd suggest doing so in your license.txt file or in an edited readme.html file. Very nice touch giving a credit roll :-)
Overall: A very inconsistent experience, yet a fairly fun one. I can tell you've put a lot of time into this, and with a bit more polishing I'm betting it could shape up into an amazing mod. If you need more specific information on my comments/suggestions please post and I'll get to them when I wake.
If I knew then what I know now I'd tell you that the story's true. Cause whatever you do, it comes back to you. -Slaughter, Burning Bridges
computer science.
