Nice guesses, but unfortunately aren't correct. I actually haven't installed 0.98.16 yet because the FAQ currently recommands of not using it, and tried both 0.98.12-blip AND 0.98.15-rerecording. Also the Enter explanation isn't correct, since the game boots only a grey screen from File/Open, while other ROMs do not.
Just noticed there was a message log in FCEU. Here is the output with 0.98.15-rerecording:
Loading C:\TASVideos\fceu-0.98.15-rerecording\Startropics (U).nes...
PRG ROM: 16 x 16KiB
CHR ROM: 32 x 8KiB
ROM CRC32: 0x889129cb
ROM MD5: 0xb1eddbb71994db079aa1dc16c05e7de5
Mapper: 68
Mirroring: Vertical
The iNES header contains incorrect information. For now, the information will be corrected in RAM. The battery-backed bit should be set.
Maybe it has something to do with the incorrect header?
If somebody can get it to work, can you send your own message log to compare values?
Oh also I wrote CRC in my first post all the time, I meant checksum. My bad: the FCM only gives the checksum.