Deciding what game to buy

I'm in my upper 40s. I uses to be a big video game player. I don't want to waste money buying a game system then buying game carts . I like those game systems that already are nodded but sometimes are terrible sound or small screens. I'm thinking if a Chinese 1000 retro portable or just a retro under $15 will do. I get bored easily. I did find Google Play Apps with loads of games and free. But its hard sometimes to play with a touch screen.