I posted this over on NESWorld and figured I might as well post it here as well:
jbholio figured out a while back that there were possibly two batches released of games (with slight differences in-game), and I think I can definitely confirm that with a 2nd copy of El Monstruo de los Globos (Balloon Monster) that I purchased recently. I haven't compared the gameplay yet as my converters are stored away, but here are some exterior and pcb differences:
1st release:
Main label missing a bunch of text (which all my other gluk carts have, so this must be a real early release?)
Original CN-05 label underneath Gluk Video label.
Bulky short black screws (when opened up you can tell that they are not perfect fit for the case)
PCB:
Actual (windowed??) EPROMS, and you can tell that the board is much older
2nd release:
Main label has extra text
No original label underneath
2x Thin and long 1x short silver screws (perfect fit for the case)
PCB:
Cheap board with no EPROMS...not sure what they're called, those two black spots of solid that looks like liquid...board also looks almost brand new
I don't know how far apart these were released, but given the different type of boards...I think a number of years. My guess is that Gluk Video released them originally in the early 1990s when MegaSoft/Caltron was developing these games, and then later rereleased them with cheaper PCB etc.
I'm gonna look for a converter in a bit and test them later today....curious to see which differences there are.