Sonic the Hedgehog 1 and 2, audio and game progression issues

[TwoSpacesSG]

Sonic 1 (Parts 1 and 2), high-end versions

• Various gameplay elements rely on the unlocked framerate being capped by the phone's CPU, however freej2me's framerate limiter lowers the framerate of the game in addition to limiting it. Examples of things needing to be limited are Sonic's invincibility frames, moving objects (platforms, moving spikes), the animation of the big ring at the end of the stage when you have 50 rings or more (can be achieved in Green Hill 1 rather easily on easy difficulty mode). Some versions like Sony Ericsson 240x320 don't have any unlocked FPS stuff, but most do.
• After the music tracks' intro plays out, the main loop does not start.
• The invincibility music has the position marker jump around for some reason. There's an invincibility powerup at the very beginning of Green Hill 3 (in Part 1) hidden in a tree reachable with a jump.

Sonic 2 (Dash! and Crash!), high-end versions

• Beating a stage softlocks the game. This is likely audio-related.
• Like with Sonic 1, the main music loop in the stage does not start after the intro plays.
• There are performance issues in Mystic Cave (in Crash!).

[AShiningRay]

Another great report. Thanks for the contribution!

Audio is definitely a pain point in FreeJ2ME at this time. So much so, that running it on Java 22 makes the whole subsystem a lot more performant and reliable than Java 8, not sure why yet... that may very well be why those Sonic 2 jars are softlocking, although i'll have to test these at some point to be sure.

As for the framerate cap, that's a troublesome one too, as FreeJ2ME-Plus just got a commit vastly improving the cap a while ago, but said cap only really helps with smoothness, the overall inner working is the same, just much improved. Right now, i don't see how a different frame cap could be implemented in a way that fixes those issues you've experienced, although i also need to test this one myself to see what's happening and hopefully how and why it's happening.