Do you remember the old Classic DOS games like Price of Persia, PAC-MAN, Street fighter, Aladdin etc. ? Now you can play them online for Free. The archive.org website now. The MS-DOS Games shows more than 2500 results.
Download size of games are different, you need not to keep it in the PC and open it in MS-DOS, you can play it on the browser itself.
You may have a look here for your old favorite game https://archive.org/details/softwarelibrary_msdos_games/v2
From the website
Software for MS-DOS machines that represent entertainment and games. The collection includes action, strategy, adventure and other unique genres of game and entertainment software. Through the use of the EM-DOSBOX in-browser emulator, these programs are bootable and playable. Please be aware this browser-based emulation is still in beta - contact Jason Scott, Software Curator, if there are issues or questions.