Now, new game include some code can detect it's orginal cartridge or flash cart. When game running, these code will detect the cartridge, if it's flash cart, it will stop to work, that why some game can play, but after stage 1 will stop working. This call Anti-Piracy.
As I know, the Anti Piracy has three methods.
1. Check the cartridge speed. (all flash cart need patch, include DSTWO)
2. Check the difference from orginal cartidge and flash cart. (DSTWO cpu can emulate orginal cartidge, no patch need, others flash cart need patch.)
3. Check the CRC, if game pacthed, it will not work. (DSTWO can auto run in Intelligent clean mode)
Actually, method 2 use most. Utilizing the CPU, DSTWO can emulate orginal cartidgecan, pass through and bypass any anti-piracy measures which is the first cart to do so. Most of the games will never need to be patched to run. So DSTWO compatible will be the best and the fast.