BIGHMW: Bomb Jack looks cool. I wonder if the 5200 could actually do it well?
I also second Marble Madness (w/ Trak-Ball support), Crystal Castles (w/ Trak-Ball), Galaga and (if it would run on a 5200) Space Harrier. And how about RealSports Air Hockey (instead of RS Hockey)???
Instead of Gauntlet, how about a conversion of Dandy? I imagine it would still support four players and you wouldn't have to reach for a keyboard to set off bombs or restore your health.
As I understand it, any time speech is used in a game, it takes so much memory that the game usually needs to freeze for a moment to let it happen (ex: Berzerk).
Would it be possible to make a decent three-player Rampage? I've heard mixed reviews about Rampage for the Atari computers...some like it, some don't. I think that version has a two-player mode.
How about porting over that XL / XE Dr. Mario some people made a few years ago? And I've never been able to find out if this version has a good two-player mode. And could the game be expanded to add up to four-player capabilities?
Cafeman: RS Football has either a two-player mode or a one-player "practice" mode (where you pick plays for offense & defense but can only run offense). This game moves slowly and it would be cool to see someone make a better football game. I don't know if the 5200 could do anything that plays like either Tecmo Super Bowl or 10 Yard Fight, but either of these would be a nice addition for the system. If anyone ever does make a new football game for the 5200, they should do the right thing and take their inspiration (and player rosters) from the short-lived United States Football League, which was active around about the same time as the 5200. So my last suggested game title is USFL '84.