Is there a PC game that has the horton 229

Your best bet would be Blazing Angels 2: Secret Missions of WWII, but I belive there is a mod for one for Microsoft flight simulator (FSX). Here's the link: http://www.planesimulation.com/fsdownloads5/FSXa1x14.htm
The horton will be the 7th down. (Personally I would go with the former) Good luck!
And just for good measure, here is a list of the planes you can fly on BA2:
Allies  United Kingdom

• Avro Lancaster *
• Boulton Paul Defiant
• Bristol Beaufighter
• Fairey Barracuda
• Fairey Swordfish
• Gloster Gladiator
• Gloster Meteor
• De Havilland Mosquito
• De Havilland Vampire
• Hawker Hurricane
• Hawker Tempest
• Hawker Typhoon
• Supermarine Seafire
• Supermarine Spitfire

 United States

• F2A Buffalo
• SB2A Buccaneer

 Soviet Union

• Ilyushin Il-2 Lavochkin La-7
• Petlyakov Pe-2
• Yakovlev Yak-15

 Axis  Germany

• Daimler-Benz Projekt C *
• Daimler-Benz Projekt E *
• Dornier Do 214 *
• Dornier Do 335
• Focke-Wulf Fw 190
• Heinkel He 111 *
• Heinkel He 162
• Heinkel He 219
• Henschel Hs 129
• Horten Ho 229
• Junkers Ju 87 Stuka
• Junkers Ju 88
• Messerschmitt Bf 109
• Messerschmitt Bf 110
• Messerschmitt Me 163
• Messerschmitt Me 262
• Messerschmitt Me 321 *

 Japan

• A6M Zero Aichi B7A
• Aichi D3A
• Aichi M6A
• Kawanishi H6K
• Kawanishi N1K
• Kyūshū J7W
• Mitsubishi J2M
• Nakajima B5N
• Nakajima J9Y
• Nakajima Ki-43
• Ohka *

* Plane appears in the game but cannot be piloted.