Klax on this game cart is good, challenging, and worth playing. Marble Madness; however, fails to measure up to the GBA.
--But Marble Madness is only 1/2 of this game cart so before you walk away, take a look at the other game here...Klax.
Klax is actually pretty good! It's addictive and fun and the reason for buying this game cart. For those unfamiliar, Klax is a puzzle game where colored tiles come toward you on a conveyor belt. In front of you (bottom of screen), you have 5 spaces on which to drop the tiles. The object is to group tiles together according to color. Three across horizontally is worth a certain number of points, three stacked vertically is worth another number of points, three diagonally is worth even more points, etc. The groups can increase to even 4 or 5 matched tiles in a group. The beginning of each "Klax Wave" will tell you what types of groups and how many you need in order to pass the wave. Of course, as you advance each wave the conveyor belt speeds up bringing the colored tiles to you faster and ever shortening your decision-making time (much like Tetris)! Klax is highly addictive!
Overall, Midway (and their cohorts on this job: DSI Games and Frame Studios) could have done a MUCH BETER job of porting these games to the GBA. Even so, if you're a puzzle game fan, this game pack is worth picking up for Klax alone. I would not pay more than $10 (at the most!) for this game cart since Klax is the only game on it worth your time and; therefore, this should be considered a SINGLE game cart and not a duel game compilation.