Iron Soldier 2
The graphics are slightly better in this version, however. Many of the buildings now have texturing, and the enemy tanks and planes have a higher resolution of textures. Also, the backgrounds are not as cartoony as in IS1. Sounds and music are better as well considering the CD media it's coming from. The FMV is quite unnecessary, and if you're looking to get this game in cartridge form, that's the only thing missing.
If you already have IS1, and are looking to continue the fun, get IS2.