Still playing but it would've been a much better game if you didn't keep falling into endless pits almost every single second. The first 2-3 stages don't have this problem but every stage afterwards suffers HEAVILY from this ESPECIALLY Stage 4: Night Carnival IMO. It makes the game very frustrating and it gets to the point where I'm trying to go as slow as possible to avoid falling, which obviously kills the purpose of what a Sonic game should be. At the very least though, the gameplay mechanics, like the trick system, the special stages, and bosses are fun to play through.

The story is nothing special but it's the first game in the series that introduces characters from different dimensions like Blaze, who is a great character and arguably the best female representation in the series, and also introduces Dr. Eggman Nega.

This game is also the first game in the series to use the boost formula which paved the way for future Sonic games like Unleashed, Colors, Generations, and Forces.

Overall, it's a good and fun game (ATM) but suffers from its level design, which brings the game down A LOT unfortunately. What starts off as a great Sonic game, halfway through felt like they just gave up on making good stages and it shows. At the very least, the setting and style of each stage in the game is unique, especially when compared to a lot of the recent games in the series.

UPDATE: I'm never playing Altitude Limit again.