Hi there, I registered just to say "thanks" for this. 
Well, that, and also to report a bug and request a few features:
BUG: If Java 11 JVM is used, the asset extraction fails with an error that says, "Unable to patch file gfx/lemming/lemm_basher_2p.png. Size of source differs from that in patch header." It works if I use the Java 8 JVM instead. I suspect something got deprecated between Java 8 and Java 11 and no longer provides its old functionality. Since I didn't experience the same problem in Michael J. Walsh's Lemmini fork, I'm thinking that maaaaaybe this commit might fix it.
Feature Requests:
Well, that, and also to report a bug and request a few features:
BUG: If Java 11 JVM is used, the asset extraction fails with an error that says, "Unable to patch file gfx/lemming/lemm_basher_2p.png. Size of source differs from that in patch header." It works if I use the Java 8 JVM instead. I suspect something got deprecated between Java 8 and Java 11 and no longer provides its old functionality. Since I didn't experience the same problem in Michael J. Walsh's Lemmini fork, I'm thinking that maaaaaybe this commit might fix it.
Feature Requests:
- Hotkey for "restart this level" (Michael Walsh commit)
- "Play Level" on the home screen should fetch last difficulty and level for the current player and jump to first unfinished level. (Can be adapted from this Michael Walsh commit)
- Fullscreen and integer scaling options (Can be borrowed from Michael Walsh; spread over several commits)
- (Really, lots of Michael Walsh's stuff looks worth borrowing. Except I don't care for how his home screen looks.)
- Scroll speed slider. The default is painfully slow.
- Option for xBR scaling instead of bilinear.
- It looks like someone ported xBRZ to Java, and hopefully their class is portable enough to just drop in.
- xBR looks best when scaling by a power of 2, then downscaling with bilinear or whatever to the target scale factor.
- xBR looks better when assets are scaled independently, then composited (rather than scaling the whole video frame).
- Following from the above, it might make sense to keep the scaled lemming spites in memory.
- Some hotkeys to temporarily alter the behavior of the "advanced select" feature:
- Hotkey 1: "While this key is held down, the cursor will NOT follow the highlighted lemming.
- Hotkey 2: "While this key is held down, the cursor will NOT follow the highlighted lemming, and only a lemming that is facing LEFT can be selected.
- Hotkey 3: "While this key is held down, the cursor will NOT follow the highlighted lemming, and only a lemming that is facing RIGHT can be selected.