The watch itself is surprisingly fun and, for an LCD game, it controls pretty well. There are four levels of difficulty as you fly through Corneria. The objective is to shoot enemies for points (max score is 1999) while dodging falling towers and replenishing resources on your way to the Attack Carrier.

Below are a few pictures from the back of the smaller sized Corn Flakes boxes which didn't have the watch offer.

As of 2019, these watches are now 26 years old, and a quarter century of plastic degradation is huge. The bodies seem OK, but the bands are getting sticky as they leach out their plasticizer. This is a common problem with many old toys.

Regarding battery replacement, the store-bought watches are the easiest to replace batteries in because of their convenient compartment. You only need to remove one screw, and the battery is a commonly available LR44 type.

The cereal promotion watch is much thinner, and requires a correspondingly thinner 389 type battery. Additionally, you will need to remove 5 screws. 4 of these will be for the watch back cover itself, and one more on the battery clasp.