There's a Playstation game called 「オレっ！ トンバ」 or "Ore! Tomba". My questions are, what does "ore" mean? And why are they using a Hiragana mini-tsu (っ) instead of Katakana? How does it make the word different? Thanks.
I'm not sure -- but I have seen that style of [オレっ] in other contexts and couldn't quite figure it out from the grammar there either. In some cases, it almost looked like the っ was being used as a possessive, a katakana の , but it may just be for emphasis (?)
Ore means I or ME in Japanese. It's just another way of saying I in Japanese, just like Watashi, for example. (there are lots of ways)
And the little hiragana -tsu thing you are talking about isn't pronounced.
In hiragana, you have 2 kinds of these tsu symbols, the big tsu(which is pronounced as tsu) and the small one you are talking about.
This small one indicates a quick stop in a word, a swallowing stop(you don't have to really swallow, though), more a terse silence.
I don't think it's for a stop in this case since you also have the exclamation point. Anyway, an internet search on オレっ reveals hundreds of other examples....so someone is bound to come up with an answer eventually.
If I may interject... っ and ッ in Japanese are only used to double sounds, the same way we double letters in English. 切手(きって; postage stamp）is uniformly written kitte in romaji. When is appears at the end of a word with nothing after, it simply means that the last sound of the word is elongated. So in this case, your オレ is more likely a cry like hey! or yo!. You can see it very often on Japanese TV or manga--cries such as Aaaaaaah! written ああっ！ Same thing here. I don't think it means "me" or "I" in this case, as it doesn't make any sense, anyway.