This fangame is good. Now someone pointed out some improvements that this game can use like improving the levels and changing stuff like the special stages and structure which I tend to agree with because there could always be significant improvements made to this like the backgrounds of some zones. For example, I would love the outside background of Rusty Ruin Zone Act 2 (which also appears in Spring Stadium Zone Act 1) to be replaced with a different background that looks more exciting and has some mountains because I tend to not like the current background right now but the new background can still be the evening background. The background of Volcano Valley Zone Act 1 could also go for some improvements because I would love to see the volcanic mountains from the outside background of Tidal Tempest Zone Act 1 to appear because they seem to be useful for the outside part of VVZ1's background. Perhaps those volcanic themed mountains from Tidal Tempest Zone Act 1's outside background can either replace the entirety of the Marble Garden Zone mountains or the front part of Marble Garden Zone's mountains can still be kept while the back ones are replaced. I'd go with the entirety of Marble Garden Zone's backgrounds because I think the background would look better with the volcanic mountains from Tidal Tempest Zone Act 1's outside background and some modifications can be made like removing the crystals that are on the bottom of those volcanic mountains. Gene Gadget Zone Act 2's outside background could also go for some improvements as well I would love to see the current bottom part replaced by the bottom part that's seen in Chrome Gadget Zone. Now some changes to music would be useful as well because I would love that in the Genesis set of songs that the Sonic 3D Blast invincibility theme to play for when the player is invincible while the music can speed up for when the player is on speedy shoes and the music for the mini-bosses is what I would love to be different while the Boss 1 theme is played for the main-bosses of the odd-numbered zones (including Panic Puppet Zone) just like in Sonic 3D Blast (Genesis) when the music mode in Sonic 3D in 2D is set to the Mega Drive version while the theme for the mini-bosses is the Sonic 3 Mini-Boss theme or a composed song made for Sonic 3D in 2D that can play during the mini-bosses of Sonic 3D in 2D. Thank you for taking time to read this comment. Hope it helps.