Reblestar: Tactical Command is played similar to Fire Emblem.
Different types of guns/explosives/grenades/some knives (weapon level with that type of weapon determines how well you can use a weapon)
Your characters gain experience and level up, improving their stats
Accuracy of an attack is determined by what the weapon is, your character's weapon level with that type of weapon, and distance from the enemy
There are terrain features like walls (some walls can be blown up), trees (some can be burned), sandbags, and more. These work, of course, to help cover you.
Your characters have Action Points, which are used to do everything. Their action points refill at the start of your turn.
When a character's HP hits 0, they are KO'd for the rest of the stage. Medi-kits can restore health if the character isn't KO'd.
Also, this game was probably to...ambitious for the GBA. It lags at times >_> Still, its fun.
Sigma Star Saga
The overworld like an RPG overworld, with enemies, puzzles, gun-data (your ship uses a combination of three types of gun data to determine how it shoots, what it shoots, and what happens when the shots hit), etc. You gain no experience in the overworld.
Random encounters and boss levels are different, however. They're space shooter. You get a random ship (could be big, small, fast, slow, balanced), and your gun data you have assigned determines what you shoot. You gain experience in these.
I like this game.