Ah, the GBA, so many great games, so many wasted hours. Here's a list of my favourite games that I've just remembered scouring through G-Online. These aren't all my recommended games, just those, like the topic implies, that I think were under-rated or overlooked by many.
The first Need for Speed by Pocketeers
- One of the best realistic racing games on GBA, I didn't like the 2nd for some reason though
Stuntman
- impressive visuals from Velez and Dubail
Klonoa's
- get's repetitive but a nice platformer
Konami Krazy Racers
- excellent kart racer - preferred it to Mario Kart GBA
V Rally 3
- Another great racer with amazing visuals (this team should really work on DS!)
Denki Blocks
- just remembered this one! GOTTA put it back on my GBA!
Asterix & Obelix XXL
- Is this a GBA game or PSX game? The game plays just as well as it looks
Go Go Beckham! Adventure on Soccer Island
- Don't let the name put you off, this game is an EXCELLENT cute platformer/puzzle game, one of the best GBA games IMO - from the team that made Denki Blocks
Ecks vs Sever 1 + 2
- These are great FPS's on the GBA, I loved these two)
Kill.Switch
- Don't let the 3D put you off, this games engine is excellent once you get used to the controls its a brilliant and highly playable 3rd person shooter
Blender Bros
- Nice cutesy platformer with a collectible critters
Sheep
- Cute puzzler
Disney's Lilo and Stitch
- Brilliant platformer/shooter
Aero the Acrobat
- If you didn't play it back in the day, here's your chance!
Comix Zone
- Copy & paste above description
Motoracer Advance
- Nice engine and nice game
Tomb Raider
- Not as bad as you'd think
Karnaaj Rally
- Nice top down racer
Sabre Wulf
- Nice platformer/puzzler
Jazz jackrabbit
- Actually I didn't like this one a whole lot, the original is still the best. But this one isn't too bad i guess.
Ninja Cop / Five-o
- nuff said!
Crazy Taxi Catch a ride
- Not the best engine, but fun for a quick blast
Ice Nine
- Best GBA FPS hands down
Guru Logic Champ
- Best GBA puzzle game?
Payback
- GTA clone with a nice engine, that unfortunately is a little overkill and often distracts from gameplay
And the rest ..
Crayon Shin chan
Disneys Kim Possible
Prince of Persia
Corvette
Mr Driller
That's all I can remember/see right now. I'm sure I missed tons though.